From what I can tell, this team is stall. From now on I’ll be rating it as such so please keep that in mind.
MANDIBUZZ (AROMATISSE) - You already have a bulky cleric in Umbreon, and Aromatisse doesn’t really add anything relevant enough to justify using both. Instead, use Mandibuzz, the most viable staller in RU as of now. Here’s the smogon suggested set:
Mandibuzz @ Rocky Helmet
Ability: Overcoat
Impish Nature
EVs: 184 Spe/248 HP/76 Def
- Taunt
- Toxic
- Roost
- Foul Play
GLIGAR - You always want some speed investment in tanks so that you can outspeed certain threats. Factoring this also in your EV spread, try going for 252 HP/200 Def/56 Spe to outspeed Adamant Pangoro and Adamant Bewear. Replace Hyper Cutter, which is normally only useful against Intimidate users, for Immunity, which stops Gligar from getting poisoned, which is quite common because of its tremendous bulk.
UMBREON - Your set is 100% smogon approved and fits perfectly with your team.
PYUKUMU - Counter is probably there to stop Pyukumu from getting completely shut down by Taunt, but either way Pyukumu always switches when it gets Taunted. Instead, use Block to ensure you’re opponent takes Toxic damage every turn and also remains a Water Type from Pyukumu’s Soak. Other then that, this Pyukumu is also OK.
MOLTRES - You’re using a scarfed set, which is not at all viable on a stall team. Instead, use a defensive Moltres set. (Substitute + Toxic.)
Moltres @ Leftovers
Ability: Flame Body
Timid Nature
EVs: 80 SpD/252 HP/176 Spe
IVs: 0 Atk
- Substitute
- Roost
- Toxic
- Flamethrower
STEELIX-MEGA/BLASTOISE-MEGA (EMPTY SLOT) - For your 6th and final spot, I suggest Mega Steelix. You were missing a mega, and Mega Steelix is the most viable defensive mega in RU this season. Here’s the standard smogon suggested set:
Steelix-Mega @ Steelixite
Ability: Sturdy—>Sand Force
Adamant Nature
EVs: 220 SpD/36 Atk/252 HP
- Heavy Slam
- Earthquake
- Curse
- Stealth Rock
Since you already have a Ground Type Physical Wall in Gligar, you could choose to use Mega Blastoise instead. If you need a set, go here. https://www.smogon.com/dex/sm/pokemon/blastoise/