who to give distant counter?

DC is nice with Azura because of the triangle adept weapon, so you can bait red mages and I don't know sword users because her def is low. But I will say Azura or Effie or Joshua.

I am actually in the same spot with an extra Hector I got. Ayra DC is the meme team that makes Tier 20 harder, You really want to give it to someone with either good bulk or the ability to destroy after being hit only once. A lot of the ones on that list are not really worth, like Chrom, Sharena,Roderick (Firesweep), Hawkeye, Cherche (Since she would prefer Death Blow or something for player phase), and Camilla is pretty trash.

Out of all of those, I say either Ayra, B!Lucina,Joshua, both Azuras, non-brave lance Effie, or Amelia. Specially both Ayra for a hard unit to deal with and Amelia for a great Armor Emblem team.

However, if you REALLY like a unit and want to use it like the madmen that put DC on Tobin, that's another fun option.

Sheena is imo the unit who would benefit the most from distant counter because she has a great defense spread of 33/36 and she can run quick riposte to one round majority of enemies with slaying axe+ and ignis/glacies(+res).

Amelia, Effie, and Sheena are probably the best candidates. The likes of Elincia, Cordelia, Lucina, and especially Chrom and Cherche do not belong on that list. They can't survive almost any attacks, magic even less so, so Distant Counter is a complete waste on them. The only one who could argue it being even slightly useful is Chrom to counter Archers.

Hawkeye could work too, in addition to what other people have said. For example +res -spd Hawkeye does quite well with DC, he's surprisingly bulky

Ayra, Sheena, and Amelia all look like good choices to me. Sheena would benefit the most if you’re going for an enemy phase focus defensive unit with her great 36,33 statspread, but Ayra and Amelia can be mismatches on both the player and enemy phase. I managed to snatch a Hector from the banner and give his DC to Amelia. She's an absolute tank and I have no regrets of my choice. I've gone against distant counter Ayras several times in arena, and they can be incredibly frustrating to deal with. Unfortunately, I don't have an Ayra of my own. Personally, I'd go with Amelia, but I'm more than biased.