Any units which torment your summoning?

Boey and this dude. Sometimes Soren but not as much as the other 2.

I'm hoping I free summon Silias for Even Def Wave.

If you count 5*, then Luke and Saber.
If not, then Jagen and Laslow.

I mean, I like Laslow/Inigo as a character but I'd much rather use his dance version.

Lately it's been Oscars and Rodericks, which is fine. The most recurring over all goes to Seliph, Henry and Selena.
Cherche and Clair are pretty good units btw.

I know people are merging her due to high BST.. but

Effie.

Haven't had any issues in this department. Maybe I haven't been in the game long enough, but I don't think I have 11 copies of literally anyone, not even if I count copies I foddered or sent home.

Also, I tend to find ways to use even stuff like Bartre for fury 2 or Jeorge for a potential hone spd 2. If all else fails, 4* merge.

I got so many of them i can make both of them into +10 if not for my feather, eirika and male morgan, and i'm still on my way into +10 marth (still at +8)