Omastar

[Angelic Diablo]

Let's get right into it...

Omastar@Leftovers
Calm Nature (+Sp Def, -Atk)
EVs: 252 HP, 252 Sp Def, 6 Sp Atk
-Surf
-Spikes/Stealth Rock
-Wring Out/Knock Off
-Rest

125 Base Def and 115 Base Sp Atk make this thing a beast, adding Sp Def and HP EVs adds durability, and with the possibility of either a speed or sp defence boost due to weather he could be quite the monster

Only problem is I have no idea what moves to have, Rest is there for recovery, and he should be able to last two turns asleep as long as he ain't being hit with Energy Ball/Grass Knot

 

[Samson]

giving him max sp def is definitely new and workable, but the issue is that omastar won't be able to otherwise take STAB earthquakes and cross chops/close combats, which renders it quite useless.

i'd suggest going bold and if you really want it to take special hits as well, just pair it up with hippow/ttar. you could stay with Calm and use it with Hippowdon. hippowdon being a physical wall and omastar doubling up as a special wall + special attacker.

wring out is not preferable. i'd give it ice beam. as of spikes/stealth rock, i much prefer stealth rock on it. you could probably even go with toxic spikes. also, i'm not a big fan of rest. i'd much rather replace rest with knock off.

omastar is really difficult to be effective as, i'm sure you know, it's weak to some strong physical types (EQ, CloseCombat) and some preferred special attacks (tbolt, energy ball). you really have to use it so that it can set up for the rest of the team and peacefully die out. that's why i run mine with toxic spikes. nothing with access to rapid spin (besides starmie) is going to like having to come in against omastar which means good poison damage.

 

[Angelic Diablo]

would 252 HP, 104 Def, 152 Sp Def be any better... and I'm breeding for a Bold one as well