How to do boss skip glitch:

• Avoid hard saving at any point, do not use a save slot (pressing B on crystal and then canceling is fine to set teleport point for Dew from World Tree and for healing)

• Die at boss

• When prompted to restart boss battle select no

• When prompted to restart from last save select yes

Then you will spawn in the boss room with 0 hp and can move to the next room to skip fighting the boss entirely. The drawback is that the character sprite will now be invisible except for the weapon/shield and ribbon. Setting a hard save and then reloading will return the character sprite to being visible again. I haven't tested this on other bosses, if all bosses are skippable with this method then the sprite would have to be invisible for the entire run, in that case, equipping armor might be good enough just to see the hitbox of the player character.