But you do need skill inheritance 🙁 Not much though, we just need Obstruct 2 on Felicia (which you can get from a 2* Hana) and Fortify Res on Wrys or whoever your rehabilitater is, along with the spur res seal. Basically we want Felicia to be absolutely ripped in regards to resistance.
Whatever you do, just make sure Felicia has 39+ effective resistance. You might not need to get Fortify if your Felicia is +res, since the one depicted here is neutral.
Feel free to leave a comment! It took me three whole potions to get this working :')
EDIT: Forgot to mention the merges don't matter! This Felicia is only +1, which gives her iirc +1s to res and spd. I could be wrong though. At any rate, just a 4* lvl 40 Felicia should get the job done!