Aromatisse… I don’t like this thing: its design is weird, and is a pain in the pokeball to get due to being an item trade evolution.
Typing: New monotype! Hooray! Resists 3 types and immune to 1 in exchange for being weak to 2. Considering three of the types it resists are the popular Fighting, Dark and Dragon types, in exchange for being to the until recently rare Steel and Poison types, pure Fairy is not that bad a type defensively.
Offensively, Fairy STAB does have some problems on its own. Being walled by steel types is bad news, for they are still popular as a defensive pivot. And there are enough Poison and Fire types to make them a problematic existence as well.
Stats: What the Houndoom? That’s what I think when I see Aromatisse’s stats. That base 101 HP is nice, but is let down by average (82 SDEF) to below average (72 DEF) defenses. Base 99 SATK is definitely usable, but still leaves you wanting, while its below average (72) ATK should be left for the dogs. Finally, how the heck is this thing slower than Magcargo?! At base 29 SPD it is blistering fast in Trick Room and Magcargo (1 point difference) slow otherwise. I think Aromatisse is supposed to be some sort of tank with a heavy support emphasis. But that feeling comes more from its movepool and abilities, than its stats.
Moves: Aromatisse has quite a somewhat varied special movepool. In addition to the obligatory special STAB, it possesses Psychic, Psyshock, Thunderbolt, Thunder, Flash Cannon, and Energy Ball. That’s pretty good, but its support movepool puts that to shame. In addition to the standard WTPS, Aromatise possesses Heal Pulse, Aromatherapy(!), Misty Terrain, dual screens, Trick Room(!) and Wish. There is also Aromatisse’s signature move Aromatic Mist, but seriously, the benefit is way too small and you are better off using Light Screen.
Abilities: Aromatisse’s abilities were built for doubles. In fact its default ability Healer is basically a Shed Skin for allies in doubles. Aromatisse’s hidden ability, Aroma Veil is usable in singles as well as doubles, but the benefit is even smaller. Of the moves it blocks, the only common ones are Taunt and Encore. A party wide Taunt block can be useful, depending on the makeup of your team, but Aromatisse will almost certainly get mileage out of it.
The Verdict: “This smell is characteristic…” Aromatisse by and large is built for support, but can hit when need be. It’s somewhat bulky, but shouldn’t be a chore to take down… This thing just confuses me.
P.S. courtesy of bulbapedia, here is the list of moves (effects?) the Aroma Veil blocks; Taunt, Torment, Encore, Disable, Heal Block, and Attract.