Status aliments can screw with the team. I.e. T-Wave Cresselia and Bliss stand out. CroCune >>> SubCune could help out against both.

Suicune @ Leftovers
Ability: Pressure
EVs: 252 HP/232 Def/26 SDef
Nature: Calm (+SDef, -Atk)
-Calm Mind
-Sleep Talk
-Surf
-Rest
And I'm sure Scizor could have another in it's place. Maybe if you do not wish to switch up Suicune's set, try a status absorbing Heracross:
Heracross @ Choice Scarf
Ability: Guts
EVs: 6 HP/252 Atk/252 Spd
Nature: Adamant (+Atk, -SAtk)
-Megahorn
-Close Combat
-Stone Edge
-Sleep Talk
Two Choice Scarfs seem redundant, but at least this can help stimulate some ideas.
But if switching up Suicune is to your liking, you could also try Lucario in place of Scizor:
Lucario @ Life Orb
Ability: Inner Focus
EVs: 6 HP/252 Atk/252 Spd
Nature: Adamant (+Atk, -SAtk)
-Sword Dance
-Close Combat
-ExtremeSpeed
-Crunch/Stone Edge
And I'm not trying to imply that Scizor needs to be replaced, he just seems to be the weakest link seeing that others might play his roll better.
I also second Dark Azelf's mention for Fire Blast on Chomp.