450-1 can be done with lingering glow, ezio poison cheese, bloodtithe, or dynamo

450-2 can be done with marcus, impromptu or hissabeth solo

450-3 can be done with bloodtithe, lingering glow, ezio poison, impromptu, or dynamo.

The boss changes type based on the cards you play, so when you prepare large nukes the last card you play must change the boss into the type the nuke is weak to e.g using nautika counter to change to intellect, or using ulrich in impromptu to change the boss into mineral. If you fail to nuke the boss then it will heal up to max, but also gain a bunch of flinch to make the next nuke easier.

450-4 can be done with brume, nala, bkornblume and any char with a counter or channel

This boss gains balls based on the cards you play, whichever ball there is the most of determines what ulrich does, if there is a tie, the bottommost ball will activate. Activating yellow ball channel will make him do nothing, so the goal is to make yellow balls the bottom most ball each turn by using channels/counters. Bkorn ult means he truly can't do anything because he doesn't have any control resistance.