I'd prioritize giving DC to a unit that actually benefits from being able to counter at range and is a character you use often, so you get the most out of it (ideally someone you can merge). That's kind of obvious but I see a lot of people committing to DC on stuff like Myrrh and Ayra, units who are good and optimally want DC, but aren't units they might use or merge often enough to justify it. Likewise you'll see stuff like DC Marth, who benefits from it for Arena scoring purposes but doesn't really need to be countering ranged units. Of course realistically you'll just give DC to a unit you like, that's ultimately what it comes down to. I've got absolutely no regrets about DC Titania even though she's a pretty mediocre unit (for now) and I've probably used her more since giving it to her.
Unfortunately my free circle wasn't very kind, no greens and only 1 blue who turned out to be Effie. I'm beginning to think that I might actually get Speed Tactic before Res Tactic at this rate. Not sure I'm going to roll on this banner though since I already got a DC on legendary banner, probably going to save and see if I can snipe a Lyn next legendary banner, unless the next seasonal also has Speed Tactic. The latter would be ideal.
