Level II
Twenty Three enemies to kill. And you will have Wooden Shield Hilichurl Guard in addition to the Slimes. Use Guards as the shield from the Slimes. Pyro is your best choice.
Level III
Twenty-Two enemies, here you deal with Hydro Samachurl and Hydro Abyss Mage simultaneously with Slimes. Mages spawn after the Samarchuls died and will have the bubble around them. The best tactic is to lure them together.
Level IV
Two waves, ten enemies. Large Hydro Slimes and Mages.
Note that on every level of Genshin Impact Cecilia Garden you will have to deal with one or two creatures spawning bubbles that create other creatures. You want to deal with them faster not to fall into that spiral.
You will also need to use the characters that are the best built because the Mages, in particular, can be tough.