Can you help me with my defence team?

Hello there!

I’m not sure what to do with my defence team. For a long time I thought it was simple because I didn’t have so many options. Summon after summon my roster got filled with a lot of new heroes that are good for defence.

My current defence project once everybody is maxed (from left to right) is :
-Joon, very good holy sniper who is somewhat sturdy and blinds
-Boldtusk, very high defence and emblems to revive, buffs attack and heals
-Telluria whom I was lucky to pull last month as mana reducer, healer and aoe
-Isarnia who works well with Boldtusk and my only fully ascended 5*
-Domitia, although I’d prefer Sartana or Seshat if I had them, I like her a lot, she snipes, protects her neighbors from yellow and more importantly dispels 3.

I also prefer rainbow for defence.

But recently I got :
-Cyprian
-Boril
-Justice
-JF
-Kiril
-Sabina
-Rigard with costume
-Caedmon
-Sonya
-Kashrek
-Grimm
-Gormek
-Tiburtus
-Proteus
And so on…

So I don’t know what my best option is for defence.

I’d like to stay in platinum (my team before Telluria often goes back to the gold arena).

Here are some pictures of my roster :

Any piece of advice is welcome! Thanks for reading.