A boss/miniboss battle that requires self-debuffing?

[Own]

There isn't anything like this in the game yet, seems like it could be an interesting way to shake up a boss battle in a future. Actually using a debuff as a positive seems fun.

Examples:

The boss room is surrounded by pipes and valves. You can smack a valve to cause a nearby pipe to gush freezing air out of it temporarily, or random pipes just gush freezing air out of them at random. You walk into them, you get Chilled. The boss has an attack which superheats the room and causes it to get wavey around the edges like Pumpkin Woods. If you're not Chilled during this attack, you take serious damage. Alternative Frozen, instead of Chilled?

The boss room has regrowing mushrooms lining the edges, same kind that Autumn Hydra creates. Walk over them, blind yourself. The boss has a Medusa-esque petrification attack, stuns you or turns you to stone for a while. If you see it's about to use that attack, quickly self-blind to avoid it.

 

[The G-Meister]

There's already something similar to this. In the fight vs. Summer and Autumn, if you get trapped in Summers vines, Autumns big wind (not tornadoes) won't affect you, and I find it beneficial to just sit in them if they happen to be coming my way. Although it would be nice for it to be a requirement for a boss fight rather than an option.

The examples you've stated all punish the player for not debuffing themself. There could also be ones which reward the player for debuffing themself, a bit like the Toy Factory takes a butt tonne of damage if you feed the trains into its mouth.

Say there's a boss which... I dunno... breathes fire at you. There's also cracks in the ground around the side which cough up little clouds of poison gas, which cling to you a bit like the honey does (it'll trail behind you.) After 5 seconds, you take damage based on how much gas you have on you for every 0.5 seconds you're in it. If you can leave a trail of it and the boss ignites it, it explodes the crack in the ground, throwing a load of debris at him and some at you, in the same arc that large Frostling Scoundrel snowballs travel. Easy to dodge for you, not so much for the boss.