So, we pretty much have a big boss for every enemy type in the game - Beast, Slime, Construct, Fiend (yes, Vana is a fiend), and even Gremlin if you count in OCH. But! We're missing an undead mainstay boss! It would be awesome to add one, preferably something like the main 4-ones, one that would drop tokens when killed. I even came up with an idea of what would could look/work like.
Through the method of elimination I've decided it would be best if it was an Undead, who inflicts Stun, but his weakness' are Fire, Shock and Poison! AND uniquely - Sleep! Because Undead tend to spend a lot of time sleeping in their coffins and such. This one would have a lot in common with the standard Zombie enemy.
Would be cool if it was a Giant Skeletal Boss Enemy that lurks on top of the arena, out of reach, and he would be segmented into 3 parts - Head and two arms - sort of like the Skeletron from Terraria. It's a classic design for video-game bosses, but one that we don't have in the game as of right now. He would do that classic thing, that would slam down an arm or his head at the knights, and it would linger on the arena for a while so that they can damage that body part! In the beginning he would only use his arms, one at a time, and his head would spew the stun-breath on the knights from time to time. When the arms take enough damage - he would gain the ability to slam them both down - aiming at different targets, or slam them both at once for a bigger, stronger slam. Should he lose one of the arms - that would make it easier for the time being, disabling the double-slam move and going back to slamming down with only one arm at a time.
When he loses both of his arms - he would enter his final phase, doing face-slams, stun-breaths and some other crazy stuff you can think of! Lasers, explosions, Undead Minion summoning!
So - status effects - he could be inflicted with Fire, Shock and Poison, which would do what they always do, debuff deal damage and such, shock especially could be forcing his arms to stay down and be vulnerable for a bit longer. But on top of that I think that it would be neat if he was uniquely weak to sleep also! So - by doing sleep on his arms and head whenever possible, enough of that sleep would make his fall asleep, forcing him to rest his head on the arena, letting the knights damage the head a little before the final phase! And it would take a bit for him to wake up, so whack away at him during this vulnerable time!
Anyways - I've also thought that it would be cool and unique if his Shadowlair version (should he get one), would be uniquely able to return at the Knights the status effects they're inflicting on him! His slams and breathes would - for example - gain the Fire property on top of the Stun, during the time he himself is afflicted with it!

Once again - if you like this idea and think it's cool - It's free, I don't need any payment or such, except maybe some crowns/energy, that's always cool, some recognition in the credits or something. But what I would like most is for this game to prosper! :D
We could also use a Mainstay Gremlin boss that drops tokens, something outside of OCH, that would be nice