A slot for in my main time. Suggestions?

What other kinds of units would you like? Mixed colors? Dancers/supports? Healers? It would also help to know what skills your characters all have, but in my opinion, maybe Effie? She tanks better than Hector, honestly. And that would span also have Tana’s guidance turn out to be even better because teleporting Effie is dangerous.

I think you need a red sword/armoured units. May i suggest BK or Zelgius.

I run a very similar team actually! Right now I'm arching up on chain challenges I completely forgot about and my team is Cordelia, Hector, Arvis, actual Bridal Lyn. It's nice being able to have both healers heal each other and having good utility outside of combat.

For my Arena bonus team I have Cordelia, NY Azura, L! Ike, and Shareena. I know NY Azure isn't too common, but just having another flier in general seems to work great for flexibility and positioning.

This is super similar to a team I mained for a very long time (B!Ike, B!Lucina, Katarina, Olivia). I would absolutely suggest adding Olivia. I would bet your team operates similar to mine. Olivia makes it so that depending on what the enemy is you now can double the appropriate colored unit on your team for huge versatility. On an individual basis she turns B!Ike into a monster, hes always great on enemy phase but now he can finish off those pesky units that he cant double and get more hits in to proc aether. The Hone attack olivia comes with is a great pad and if you give her the hone attack seal she gives everyone +8 atk at the start of the turn. While she will rarely be attacking (a second turn for one of your three will usually be more effective) if you give her triangle adept she perfectly takes care of the few units green units your arvis or B!Ike couldn't take. You can double down even more and give her an armorsmasher to make her really destroy green armors.