Hm... People have already run most of the viable sets, but I may as well give my usual overall analysis.
Pros:
- Say it with me "Aromatisse is a WALL".
- Fairy typing gives it next to no common weaknesses. Making it even MORE of a wall.
- Sp. Attack makes it almost viable for an offensive wall.
Cons:
- Unlike the special attack, the movepool is almost all support moves, which doesn't give you very much room to move around and take other choices. Wall it is...
- Is going to be very predictable once the opponent knows what kinda of Aromatisee you're running.
Abilities: Healer is nice, does what Aromatherapy does, but only 1/3 of the time. However, Aroma Veil is also a fine ability, stopping your team from getting confused and maybe able to stop anti-leads or anti-walls that use confusion tactics. It could really go either way with this one, so it all depends on what kind of team you have.
Typing: Fairy, as usual is a very overpowered class, taking damage from only steel and poison, well, at least, taking a ton of damage from those two. Problem is, before fairies existed, poison and steel type moves weren't too common when compared to something like ground or fighting, people are slowly changing but for now the fairy typing just adds to Aromatisse's bulk.
Moves: This movepool seems pretty much like Game Freak wants to shove a new support Pokemon in your face. And offensive Aromatisse is barely viable when coupling the stats and the movepool. 99 Special Attack is alright, but when you've only got moves to help the rest of the team? No point in making one offensive, I'd say. Unless of course you run something like Assault Vest on it, then maybe, but Aromatisse seems created for support, so that is what it shall be.
Stats: Yeah, probably should have gone over this BEFORE moves, but eh. Moving on, Aromatisse has the stats of a WALL, well... Barely. The defenses leave something to be asked for, as both are very close to average, but the HP stands at a high 101 allowing Aromatisse to become the wall it is. 99 Special Attack also have viability for an offensive Aromatisse, but again, due to movepool, I don't suggest it myself. And don't even bother with the attack and speed. They have no redeeming quality for themselves, Speed resting at 29 while the attack has no moves to go well with it anyway.
Checking: Aromatisse is somewhat easily checked, seeing as it won't be doing a whole lot of killing to begin with. And one move will almost give away the set, so go out into something it can't effect with many of it's moves. Steel types do well here along with Fire types, both resisting any STAB that Aromatisse could be trying to use, and the former to deal some great STAB damage of its own.
Countering: One does not truly counter a wall, however, I did run some calculations:
252+ Atk Aggron Heavy Slam (120 BP) vs. 252 HP / 0 Def Aromatisse: 504-594 (124.1 - 146.3%) -- guaranteed OHKO
252 Atk Sheer Force Darmanitan Flare Blitz vs. 252 HP / 0 Def Aromatisse: 352-415 (86.6 - 102.2%) -- 18.8% chance to OHKO
252+ Atk Technician Mega Scizor Bullet Punch vs. 252 HP / 0 Def Aromatisse: 314-372 (77.3 - 91.6%) -- guaranteed 2HKO after Leftovers recovery
Now let's see how much damage it would do to others using Chu Chu Jelly's set:
252 SpA Aromatisse Hidden Power Fire vs. 252 HP / 4 SpD Mega Scizor: 220-260 (63.9 - 75.5%) -- guaranteed 2HKO
252 SpA Aromatisse Moonblast vs. 0 HP / 4 SpD Darmanitan: 103-122 (29.3 - 34.7%) -- 8.9% chance to 3HKO
... I also tried running it against an Aggron. Yeah, forget using your Aromatisse if an Aggron switches in, ok?
Overall: I stand by my conclusion that Aromatisee should be support much more than offensive, although it has potential there, it has much more in supporting your team. At this point I would also like to bring up that despite its bulk, a few, or even one, strong Super Effective hit will do the job quite easily as shown above. Aromatisse is a fine Pokemon and a GREAT support Pokemon, however when it comes right down to it, quite a few other support walls outshine it. But, even so, I think I'll probably be seeing this thing around quite a bit after a time.