I think this is the easiest way to beat zio 10-10. I dont know if the position gonna matter Hyufine [back] [fastest], Aras [right] [3rd], Bad cat Armin [left] [2nd], Kayron [front] [4th] + supp aoe reviver [pref ml Celine]. Hyufine s3, BCarmin s1, Aras SoulBurn on Zio, Kayron s3 on Zio. Hyufine s1, BCarmin s1, Aras s2 without SB, Kayron SB. After this it should enter or almost 2nd phase [deal enough dmg and rng]. If supp ml Celine save it until all your unit with mark "4" die.

Note: My Kayron use counter crit set with elysa knive, Aras lvl 50 use Bastion of hope, Hyufine use Sol Bad Guys Art

I hope this post can help someone because i really think zio 10-10 is so hard