Eye

is one of the harder bosses inside the castle.

Strategy
Eye is, well, it is an eye! And it is huge! Try to avoid touching it and jump away when it's coming and try to hit it with your Weapon of choice. Be aware, this eye splits up into two tinier eyes when it is destroyed! So will do the tinier versions. And the even tinier versions. This eye is literally a matryoshka doll!

Useful items are a good sword, Health Potions, and an Invincibility Potion. The invincibility potion's power is quickly wearing off, so one should hit fast and heavy.