Emblem focus usually go for defense 1st, then versality use for raid/war.
If you plan using atlantis family which is you already have Poseidon +20, Ursena is great pair. She is also still good on offense againts yellow hitter like Odin, Joon, Drake, etc.
I have my Ursena+20 using mana troop lvl 11, with 9 tiles, reflect yellow ready.
Another candidat is Garnet if you have Cobalt and Onyx, she is very good defense and offense.
Ureaus is also no joke he hit very hard if you emblem him +20.
Krampus is sturdy without emblem, emblem if we want to put on defense.
Mitsuko is also great like Ursena.
So, depend on who often and playstyle. All of them are great heroes.