- Rewards:
- Summons Available: Yes
Found at the end of the Academy Crystal Cave Dungeon in Liurnia of the Lakes, these bosses appear to take no damage, and so can be a frustrating fight. However, with the proper technique, they’ll go down pretty easily.
General Tips:
- Using a weapon that inflicts Strike damage will allow you to deal increased damage to the bosses throughout the fight.
- Inflicting enough damage to a boss will break its stance, which will fracture its crystalline exterior. Once fractured, the boss no longer takes reduced damage and becomes highly susceptible to stagger.
Bestial Sling can quickly stagger one of the bosses, especially if your summons are also attacking it. - If you don’t have access to Bestial Sling, equip a Strike weapon before entering the boss arena.
- If you aren’t confident in your rolling skills, also equip a shield before entering.
- Both bosses can be backstabbed.
Strategy
The strategy is the same for ranged and melee characters. As soon as you enter the boss arena, sprint behind one of the statues, putting it between you and the mage Crystalian. Then immediately summon your tankiest Spirit Summon — the 
Skeletal Militaman are probably your best choice, because they continuously revive.
Keep the statue between you and the mage, let the melee boss come to you, and fight it behind the statue — ideally with a Strike weapon or with Bestial Sling. You’ll need to either use a shield, or else be confident in rolling and using the i-frames of the roll to dodge the spear-boss’s attacks. When rolling, always roll directly towards or away from the statue so you don’t end up eating damage from the staff-boss’s spells. If the mage ends up too close, move to the other statue.
Don’t be dismayed by the lack of damage your attacks do; if you attack frequently enough, and especially if your summons are attacking the spear-boss along with you, it should stagger fairly quickly and allow you to critically strike it. Once you do this, its crystal armor is broken, and it will take a lot of damage (and you’ll be able to easily interrupt its attacks). With the Spear down, the Staff is pretty easy. Be patient and wait for it to finish a spell before attacking, and continue to use the statues to block projectiles.
Don’t forget you can backstab both bosses, which can offer you a window of invulnerability if you misposition.
Movesets
Spear
- Triple Stab – The boss does a small hop into the air and stabs its spear at its target, and repeats this three times. The third attack can break your guard, so try to roll through the stabs once you recognize the combo (it can also be the Five Stabs + Leap Attack, so be careful).
- Five Stabs + Leap Attack – Starts like the Triple Stab, but there are two more stabs, and then a leaping attack. After the leaping strike, there’s a good window where you can counterattack.
- Double Stab – Two slower stabs, with no hop — distinguishable by the longer wind-up time.
Staff
- Crystal Release – The boss forms a crystal mass above its head, and after a brief delay, crystals shoot out in all directions. Easily avoided by running out of range.
- Crystal Torrent – The boss forms a crystal mass at the tip of its staff, then releases a spray of crystals. Avoid by either spriting horizontally, or hiding behind an obstacle.
- Shattering Crystal – The boss forms a crystal mass at the tip of its staff, and slams it down in front of it. Roll away to avoid.
Also gravity magic is effective to them.
Thanks for the tip! Was there a particular spell you found effective vs this boss?