So who have other people given Wrath?

Ryoma, Lyn, and Fae

I gave one to Lon'qu, for a +20 damage Moonbow build. The other two people I want to give Wrath to are Roy (to boost his damage output in addition to helping keep his 50% QR up with Aether) and Lukas, to go with a Harmonic Lance+/Ignis/SB set with Deflect Magic to run in arena; tanks a mage and surprises the enemy with a +20 damage Ignis. Would be pretty fun, at least to try.

You don't have an extra nephenee, you have a nephenee merge.

Lyn and F!Corrin

I’ve only given Wrath to two different units, Mia and Black Knight. I really liked it on BK with Steady Breath and Quickened Pulse. With Mia, I think it really gives her the extra punch needed to tear through armors/high def enemies. I know how much you like Mia, may I suggest trying her out with Fury/Wrath? I ran Swift Sparrow/Desperation combo also, but felt like Fury/Wrath was a little bit of a step up in terms of overall power. The health loss from counter attacks weren’t as substantial with the additional stats from Fury

One on L-Ike, one on Hawkeye (merge project).
One nephenee still waiting in my barrack.

If i see a super new unit, i've got some great skills to fodder, but only for a merge project (Steady breath, wrath, distant counter, berkut's lance, chill speed, tactic speed, bold-vengeful-special fighter, guard 3... So many skills ! )

I've only given it my Soleil, still have two spare Nephenee sitting but I think I actually might merge one as i really like her.

Lyn, Caeda, Olivia, the three Main heroes (for arena purposes) are always the first ones that come in mind.

I have Wrath on Lyn because I like her, but the people getting most out of it are in general low attack characters with an offensive playstyle

I gave my extra Karla to W!Robin. His base kit and stats allow him to be a great duelist, and being +Def helps.