Add a checkpoint to ultimatum bosses

Feedback from a casual. Some context: I roll my own sorc lightning quarterstaff build and expected that it may suck and I may try harder than with pro builds. I had a really hard time with Viper Napuatzi but some dmg respeccing made it finally possible. I just beat the Ultimatum boss, but Ultimatum sucks ass.

Main problem: you have to redo the entire trial if the boss kills you.

Compared to Sekhema trial, this is why Ultimatum sucks so hard: the boss is random. Especially first timers may have to learn 3 separate boss mechanics and the chances to beat them first try are really low.

This is made worse by the visual noise from afflictions.
I got the carrion bird multiple times and I couldn't see what killed me. It has this long vomiting attack that just starts and nukes you if you don't instantly react, but with so much else going on (depending on afflictions) it's hard to react to.
One time the floating blood bubble hid the stupid dog thing.
No idea how you are supposed to dodge the bird with the huge physical damage debuff.

In the end, Ultimatum is a coin toss encounter.
Get an easy boss (chimera) and easy afflictions and it's a walk in the park. I beat that chimera the first time I got it, after dying 4 or 5 times to the carrion bird.

A bit of RNG is part of every boss, but Ultimatum feels like 80% luck and 20% skill. There are some debuffs that literally don't affect your build at all and others make the rooms themselves 3-5 times harder. Rooms alone are fine like that, but if you pair that with Elden Ring boss encounters, it just becomes a tedious chore.

My suggestions:
- let players respawn at the boss encounter. It's still a boss, it's tough – especially with bad affliction rolls.
- alternatively, disable afflictions for the boss encounter. There is so much going on already and the random debuffs, traps etc. make it not just harder, but you basically have a different fight each time – luck alone will dictate whether it's easier or harder.

As for the carrion bird: IMO with some traps or debuffs in the mix, the attacks of this thing are hard or sometimes impossible to see. I'm fine with hard bosses and having to learn their moveset, but going through all the rooms each time AND getting random visual noise and traps on top each time, no thanks. I don't even care if I never beat this thing, because the effort just isn't worth it, not when luck dictates what random bullshit I have to deal with on top. I ain't got much time for playing games as it is, I won't waste it on casino mechanics that dictate whether it will take me 40 minutes or 5 hours to get something done.