oik, now I know how many of you have been hurt in the past by Grimalkins, but read on.
I propose a massive Grimalkin, with a more tattered appearance, and a tarnished circlet around his ears as an alternate tier 1 boss. again, hear me out.

Phases

The chase (floors 1/2):

after entering the boss floor, the Grimalking rises from behind you, and your party needs to run, navigating through a maze like construct to get away. There would be obstacles like blocks and maybe a sparse enemy or two that would also attempt to block your way, cats of course. This chase would continue for a while until you come to a fairly large room.

The room (floor 3):

This is the actual -- technically -- boss fight. Around the room there are several light spawners scattered, as well as many unlit torches. The goal of the fight is to dodge the Grimalkings attacks while getting the light to all of the torches. Once all the torches are lit, the Grimalking will be stunned, start to shade in pink, and be vulnerable to attack. After a little while, the candles will all go out, and the Grimalking will be invincible again. After enough damage, the Grimalking will let out a screech, fade, and the boss token will drop. The Grimalking will, in this stage, melt through the floor like regular Grimalkins, just a little bit slower though to allow time to dodge. When he surfaces, he will either try to bite the knight in front of him, or fire 3 balls of darkness forward, and at 45 degree angles in front of him. He also - rarely - will let out a roar, bathing the candles in a sphere of darkness, putting them out and resetting the stage. There will be 3, maybe 4 cats in the room to start, with several( another 2-3?) spawning when the candles are hit, along with a howlitzer situated near the candle. The original cats will have a 30 second respawn timer. Any additional cats and howlitzers spawned by lit candles disappear with them. The candles will be the eternal blue kind, but you will still need to throw a spark to activate them. They also will go out, but they will stay on until after the Grimalking's stunned period.

Stratum/awards

• Level 1: Darkest Keep-Perilous Penumbra

  same aesthetics as candlestick keep, only with more cats, and the Grimalking follows the group.

  Level 2; Darkest Keep- Lachrymose Labyrinth

  This is the labyrinth, a sparse few cats inhabit it, the main threat is the Grimalking, which follows you quicker, but does actually slides along the floor after the party, not popping out of the ground in this level.

  Level 3: Darkest Keep- Grimalking's Grotto

  The actual boss floor, a large, darkened room with a few stalactites and stalagmites growing around. The walls and floor are the same as Candlestick Keep, but much more broken and fractured.

• Boss medal: shadow shilling: a coin radiating an evil energy

• rewards:

  1. 20 coins: tarnished circlet: The grimalking's crown, it appears as a bronzed helmet, like the Spiral Circlet, that gives protection against shadow
  2. 15 coins:Grim blade. A short sword appearing as a blade with a banded hilt(cloth), and a jagged blade with a black streak down the center;is a fast sword with a four hit, all shadow damage, combo. The charge attack creates a Grimalkin that bites down onto all enemies in front of the wielder.
  3. 10 coins: Grimalcape: An armor colored dark bronze, with larger plated shoulders, it adds 1 to life and gives protection against shadow

I need some help with it, I know, and that's where you guys come in. I really want to build this to the best it can be, so care to share feedback?
EDIT: thanks Eeyup for the whole stunned and damage thing; thanks to ghret for seconding cats, talking about howlitzers, and a slight build onto how the candles will function; thanks to Kentard for coming up with the alluringly alliterative level names, also put up his Grim Blade moveset and reminded me of attacks.