Some say that the Ainsel and Siofra rivers were both diverted to flow over the Lake of Rot, sealing the source of the rot — an outer god — within. While the Lake of Rot isn’t a particularly large area, it can be a serious hassle to get through, thanks to the Scarlet Rot that gives the lake its name. Fortunately, there aren’t too many enemies here, and we’ll tell you all about how to deal with Scarlet Rot.
The Lake of Rot is reached by following the Ainsel River through Nokstella. An elevator at the end of the river will take you down to where the Baleful Shadow spawns — beyond the shadow is an elevator that you can take down to the Lake of Rot.
While you can theoretically do this area without actually dealing with the rot (and just using flasks to heal), you’ll die a lot using this “strategy”. Instead, you should pick up Flame, Cleanse Me from eastern Liurnia of the Lakes (if you haven’t already), and make sure you can cast it. It only takes 12 Faith, but you may need to either consume runes/grind a few enemies to level up, or respec with Rennala in order to be able to cast it — you can purchase a Finger Seal from the Bell Bearing Finger Maidens in Roundtable Hold in order to cast the incantation.
If you can’t or won’t use Flame, Cleanse Me (maybe you’re doing a no-magic playthrough), you can use Preserving Boluses to cleanse yourself of Scarlet Rot. If you can’t craft these and/or don’t have many, consider heading to Siofra River and grabbing the Armorer’s Cookbook [6] for the recipe — but only if you have a decent number of the requisite ingredients (Dewkissed Herba, Cyrstal Cave Moss, and Sacramental Bud). You can also save yourself from having to cleanse the rot as frequently by increasing your Immunity stat — the Mushroom Set that you can find in Seethewater Cave on Mt. Gelmir has high Immunity stats, and you can also find the Immunizing Horn Charm +1 early on in the Lake of Rot.
Finally, using incantations that give you a heal over time (Blessing of the Erdtree, Bestial Vitality, etc) can help mitigate the effects of the rot, Although they generally won’t be able to outheal the rot, if you combine them with the Icon Shield and the Blessed Dew Talisman, you can cleanse yourself of rot on safe ground and then patiently wait for your HP to come back, saving precious Crimson Flasks.
It’s worth noting that there are numerous basilisks in the Lake of Rot, so the Prince of Death’s Pustule (or other items that boost Vitality) can be useful here as well.
Lake of Rot
Note: In addition to the tips in the “Preparing for the Lake of Rot” section, it’s useful to know that you can teleport to a site of grace while infected with rot. If you know you’re otherwise going to die, it’s a good idea to instead teleport to the Lake of Rot Shoreside site of grace — this will immediately cleanse you of rot, allow you to rest and restore resources (and protect your precious runes!).
From the Lake of Rot Shoreside site of grace, head south downhill to the shore, where you’ll find a corpse with the Map: Lake of Rot. Then look to the southeast; in the distance, you should see an ancestral follower wandering in the lake.
You might be wondering how he’s surviving out there — it’s because of a talisman he’s wearing (that we’re going to take by force). Run out into the lake and kill him, and he’ll drop the Immunizing Horn Charm +1. Grab it, then teleport back to the Lake of Rot Shoreside site of grace once more, where you can rest and then equip your brand new talisman.
Stand on the rocks by the tree on your left. If you look east, down into the lake of rot, you should see an item sitting at the base of a strange growth sprouting from the lake. Jump down and grab the item (an Aeonian Butterfly) and then start sprinting north, where you’ll find another corpse on some mushrooms with a Somber Smithing Stone [8]. From here you can go southwest, where against the wall are some Aeonian Butterflies you can grab if you want. Then teleport back to the Lake of Rot Shoreside site of grace to refresh your resources and cleanse yourself of rot.
Next, head south, down to the shore again, and look east — you should see some ruins, which is where we’re going to head next.
You’ll first see a wall, and just past it a platform with another wall. Go to the front left corner of the platform and cleanse yourself/heal, then turn around (look to the north and west) — some basilisks should be coming out of the rot towards you. Deal with them, but know that another basilisk waits on the other side of the wall behind you, so don’t kite into it accidentally. Once all the basilisks are dispatched, you can grab the Somber Smithing Stone [7] from the corpse leaning against the western side of the wall on the platform.
Go to the southwestern corner of the platform and prepare for another sprint across the rot — our next destination is the area with the small pillars and some stone ruins, south of your current location. There are a couple of basilisks hanging out near the stone ruins you’ll want to stand on — it’s best to ignore them and cleanse/heal before fighting them, since you can get pretty far up onto the ruins and be safe for a few seconds. If you want, you can grab the Golden Rune [9] from a corpse at the top of the ruins, and completely ignore the basilisks. From the corpse, sprint further south to a nearby obelisk.
At the base of the obelisk is a button, but unlike the buttons in the catacombs, this one doesn’t set off a trap. Instead, walking onto it will raise some platforms to the west. In the middle of the platforms is a sleeping (?) Dragonkin Soldier. Before you head to the platforms and begin the boss fight, figure out which Spirit Ashes you want to use and summon them. Then you can head west onto the platforms. Once you get close enough to the Dragonkin, it will wake up and the boss fight will begin.
This fight is just the first phase of the Dragonkin Soldier of Nokstella, so you can use the guide for that boss if you need help defeating the one here in the Lake of Rot. Of course, having to fight in a lake of rot does make the fight a little different. What you want to do is draw the boss to the center of one of the platforms so that you can safely roll behind its leg and stay out of the rot — besides that, the strategy remains the same.
The Dragonkin Soldier will drop the Dragonscale Blade when defeated, and you can then collect the Golden Rune [7] from the corpse in the middle of the platforms. Another corpse next to the northwestern platform has a Golden Rune [10], and a third corpse west of the southwestern platform has a Lightningproof Dried Liver. Get onto the southeastern platform and go to the southeastern corner, then look east. There’s a platform nearby — head to it, (you can wait there for your rot to dissipate if it didn’t fill your bar), then from there go to the platform further southeast. Even further to the southeast is a square pillar with a corpse at the top that holds a Somber Smithing Stone [8].
The route to the two platforms and the Somber Smithing Stone [8]
You can ignore the basilisks you pass, grab the item, and then drop down into the rot and sprint southwest. Run up the pillar that leans against a large rock, get a running start, and jump north from the rock to the leaning stone beam. Then hop onto the pillar further north, and from there onto the wall. Head west along the wall until you can jump down onto the pillar with the corpse hanging off of the edge and grab the Mushroom Crown. If the basilisks haven’t aggroed, you can teleport back to the Lake of Rot Shoreside site of grace. Otherwise, you’ll need to drop down and run out of the building and make your way back along the platforms to where you fought the boss, then teleport. (You could also kill all the basilisks and then teleport, but this isn’t recommended).
From the Lake of Rot Shoreside site of grace, head south to the shore, and look southwest, where you should see another obelisk. Run to it and step on the button to raise platforms to the west and southwest, then go northwest on the new dry land to grab some Rot Grease from a corpse there. Continue south, and three basilisks will jump out of the rot on either side of the platform. Kill them, then stand in the center of the platform and look to the northwest, where you’ll see a corpse that had x10 Black-Key Bolt — another corpse further to the northwest has a Somber Smithing Stone [7].
There are mushrooms you can stand on, safe from rot, where you grabbed the Smithing Stone — at this point, you might just want to return to the site of grace rather than running across the rot back to the platform, but it’s up to you. Either way, make your way back to the platform where the three basilisks ambushed you, and then continue to the southwestern end of the platform. From there, you can run southwest through the rot to another obelisk — hit its button and raise some more platforms!
Run to the new platform to the east, and from there you can grab the Warming Stone southeast of the platform, and then continue to the next platform and then the large platform further southeast. A basilisk will jump out of the rot near the Warming Stone, and more will pop up as you cross to the large platform. Again, you can ignore them or fight them once on dry land.
The “Large platform” is the one with the pillar in this image
From the large platform, go southwest to another obelisk and step on the button at its base. This time you’ll get a more dramatic result, as huge pillars rise out of the lake. From the obelisk you’re currently at, you can go south-southwest to find the final obelisk. Stand still once you push this button, as it will raise the platform with the obelisk and you don’t want to fall off.
Go north across the bridge and a Alabaster Lord will spawn — he has decent damage, but his swings are slow, its only ranged option is an attack that sucks you inward, and it’s easily interrupted. Kill him to claim the Alabaster Lord’s Sword. Once you’re across the bridge, turn right to head east, where you can find a corpse with a Somber Smithing Stone [9]. Now go back the way you came, south across the bridge and past the platform with the obelisk. Continue onto the platform that hugs the wall and take the ladder on the left down.
Continue east down the path, and you’ll see a loot beetle in the rot that drops a Somber Smithing Stone [6]. Further east is an area with a number of basilisks and a bunch of Aeonian Butterflies you can collect if you want, but it’s deep in the rot and it’s easy to die over there. Either way, head west from the bottom of the rock path and you’ll soon see dry, paved land on your left. Get up onto the dry land and continue west. At this point, you have a choice to make: if you’re very low on resources, you can turn left and enter the Grand Cloister to grab the site of grace, or you can head directly to the final item in the Lake of Rot.
Turn left to reach the site of grace — the structure further west can be visited before or after reaching the grace
There are a few spots of dry land northwest of the Grand Cloister’s entrance that you can use on your way to the structure circled in the image above — inside the building is a chest containing the Nomadic Warrior’s Cookbook [22]. Grab it and head back to the entrance to the cloister, making sure you get the Preserving Boluses on the right side of the entrance.
Grand Cloister
From the Grand Cloister site of grace, head west down the stairs, and continue northwest to the end of the platform. Here, you can jump west onto the ledge, then turn left and jump the gap to the south. Follow the ledge west and then north to find a Golden Rune [10], then go back the way you came on the ledge. At the gap, instead of jumping, you can drop down onto the ledge below, where you’ll find a Golden Centipede. Then go south and around the corner, where you’ll drop down to the west, to a lower ledge.
Drop again to the west, and you’ll see a couple of Pests (Lesser Kindred of Rot) on the low ground who have probably noticed you by now. Summons are available here, so if you don’t want to save them for the Ulcerated Tree Spirit that’s coming up, you can summon them now. Follow the ledge around the corner so you can drop down to the north behind the columns — this will give you some cover and hopefully let you attack the first pest before the second one can attack you.
Once the two pests are handled, head towards the river of rot and turn left to go east. There is a pest on the other side of the river, and further east past the pest is a Golden Rune [10]. The river turns left, where you’ll see another pest patrolling, and some items in a dead end. When you get near the items (Smithing Stones [6] and [7]), an Ulcerated Tree Spirit will spawn (see here for a guide on fighting this boss). You’ll likely have Scarlet Rot at this point, so run back the way you came and turn right to stand on the large square dry spot, and use Flame, Cleanse Me or Preserving Boluses.
The platform I’m standing on here is where you’ll want to fight the Ulcerated Tree Spirit (who spawns when you get to the spot circled in this image)
This version of the tree spirit can inflict rot, but is otherwise identical to all the others you’ve faced. If you die fighting it, you’ll need to respawn it by returning to where the river dead ends — make sure you clear the pests on your way back to the boss, or they’ll end up aggroing and making the fight against the tree spirit very difficult. In case you’re trying to decide if it’s worth killing: the tree spirit will drop a Golden Seed and 11,193 when it dies.
Once you’ve killed the tree spirit (or decided to leave it for later), go west, where you’ll find a bunch of the pests all worshipping towards the altar further to the west. Sneak up and backstab the closest one, then fight the other two that aggro. Repeat this until all the enemies are dead, and grab the x8 Fan Daggers and the Smithing Stone [5] from the corpses on the bottom set of stairs. Go up the stairs and into the structure at the top to find a chest containing the Scorpion’s Stinger.
Go back down the stairs and turn right at the river to head south. The river will become a waterfall, and in the middle of the river just before the waterfall is a coffin. Go around to the open side of it and interact with the coffin to enter it — getting in will transport you to the fog gate for the Astel, Naturalborn of the Void boss fight.
Warning: Astel is a tough fight, and there is no site of grace outside of his boss arena. Therefore, if you’ve got a meaningful amount of runes on you, you should consider using some Golden Runes and leveling up before you get in the coffin — that way, if you decide you need to save Astel for later, you won’t have to leave any runes in the boss arena (or use a Sacrificial Twig).
Unabashed FromSoftware fanboy still learning to take his time with games (and everything else, really). The time he doesn't spend on games is spent on music, books, or occasionally going outside.
11,193 when it dies. 
