While it's not as straightforward as Ploying the guy right in front of you, it could potentially be a lot stronger. It's mixed phase value is in being able to take some extra damage on Player Phase (if you run Close Def, for example), in exchange for a grand total of Ploying extra enemies (in this case, basically 21 less damage?).
I also like it when I can have my character take on multiple guys at once, and it gets even better if you have DC.
An actual, Arena-based example. My Libra took on a Reinhardt, Bow Lucina and Axura at once. While two of those are at Weapon Disadvantage, Reinhardt can do a nice number on him (I think 18x2 with Death Blow 4). The subsequent attacks just kept on tacking the Smoke-effect.
It's insane.
Atk smoke is REALLY good when taking on multiple opponents. It just takes so much edge out of their bite when you have at least 30-35 def because at that point usually most of their damage comes from their A-skill and weapon if they don't have triangle advantage (and possibly special, but you're using a fast tank there), which means you could be cutting their damage in half.
Or look at it another way, on a fast tank you take 7 less damage per opponent. If renewal is enough to enable a unit to fight one more time, atk smoke isn't far behind and works on multiple opponents.
When I had Felicia at 40+2 I think it was, she was using atk smoke and growing wind without a Plate refine and I threw her at the Dark Domain map (the one where Mae, Boey, Celica, and Genny camp on defense tiles behind mountains with Bruno sitting in the back). All I had to do was have Marth give her one infusion of HP because she was taking so much recoil from fury and she basically solo'd the map.
Smoke skills are pretty good, and I enjoy using them for all of the reasons that you have listed. The only problem I have with it is that you can't debuff the enemy that fought against your unit with the Smoke skill, making it a bit unreliable in your first fight.
What I like to do is carry Ploy skills on another unit so that I can debuff the first unit, have it go against my unit with the Smoke skill, and then have the Smoke debuffs be spread onto nearby enemies. (The Ploy and Smoke skills cover each other's limitations pretty well, I think.)
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