I managed to clear from 9-11 with all 3 starts (11/3 just by a second barely). However the new floors are designed to waste your time so unless you are a whale, dont bother 3 staring those.
12 -1 has the anoying flowers that keep running away and teleporting all araund the map
12- 2 Part 1 even with sucrose i had a hard time keeping mobs stacked ... also flys cause so many reactions that totaly mess you up.
Part 2 its probaly imposible without Ganyu or full cyro team (at least 2) -- Mage has a water aura with bubles, he spawns bubles that can stun you easy and it spawns a lot of monsters and only cc that works on them is ice. Also pyro mage is also there to piss you off extra as you have to use Barbara to get him down (or some electric character).
12-3 Part 1 -- Lectors are weird. My Noelle tanked 80% of the damage on them, but i had no chance of breaking their electric shields fast after they go low on hp (maybe goes faster with cyro i guess). But they are not realy a danger if you hug them and spam normal attack (it deals extra damage right now)
Part 2 -- With Jean its possible to deal damage to them faster than timer goes down, but you realy need a good shield so you can trow them in air. Its best to kill electro 1.st, then pyro and for end cyro as she will refresh her shield when her flys are alive.
Anyway -- hell no i am lvling Bennet to chesse this. I just dont see this being clear without this character. (its maybe possible to 1ko shield bosses with him)
And i am 100% you need Eula here. They want to sell her that bad.