I appreciate that having Atomos there helps the family bonus, but it is one of the worst 5* heroes in the game. You’re also missing a healer, which I think tends to weaken a team, but that’s stylistic. Ariel would clearly be an upgrade over Atomos.
There’s an underlying question, which is the value of color-stacking a defense. Normally this is a losing strategy. Ursena shifts the dynamic some, however, because of the yellow reflect. Still, 9 times out of 10, I’m using tiles from my stacked color to kill the tank, not specials. So, I’d just yellow stack against this team and probably do very well, especially if I brought a fast dispeller, e.g. Zeline, to clear the yellow reflect if Ursena lives long enoughnto cast it.
In some ways, Ursena tanking with flanking yellow is more troublesome.
Ya I hear ya I wish I had Ariel I could have a complete family lineup with only only one four star