You might want to save it for a better target?
Caeda (+6) +atk
Just as an fyi - she honestly wants galeforce setup
P!Felicia (+1) got 2 more copies +atk or +res
Since you have some copies and if you are ok with giving up SF3 fodder. Still, armors are past their time in this game. I will say she’s good in pve - I have her. Fast unit. Pretty cool. But that’s about it.
Ares +atk -spd (have considered him, but my units are quite saturated in red)
I love using DC/vantage on ares. I don’t use competitively, but he’s a lot of fun to play and is a good abyssal unit
H!Myrrh (could +1) +def
Definitely pass on her. She’s past her prime too.
And armor units like W!chrom, B!ephraim, Surtr, W!Lissa, V!Greil, Idunn.
Both Idunn and Ephraim want it the most out of this batch. Ephraim desperate needs it to be functional, otherwise Surtr is just better.
Before making a decision though, are there no infantry or other units you want to invest in that could use the DC, or the DC/SF3 combo? Something you can merge up and flower up to become a total beast? Giving the DC to an exclusive 5* is all well and good, but it’s potential is capped unless you start pulling more copies, and orbs are too rare for that. For example, the only exclusive 5* I would fodder V!ike to would be someone like Duma who is going to make your defense team a lot better and can take advantage of both skills very well. It makes Duma workable.
Otherwise though, DC can go to some interesting targets. For example, Seliph uses it well and when merged and gets his refine, becomes a very strong unit. With enough merges, he’s going to be a lot better than a lot of possible exclusives (at least until the they powercreep him). But I am just picking one example of many possible ones. It might be worth looking through the characters to see what would make good merge projects.
Also, have you given DC to your Nagas yet? That is definitely not a waste of fodder, even if it’s just to one of them. Makes astra matches a lot easier.