Politoed - I'll be providing a choicer later, and I notice your team needs some help taking physical moves, so turn Politoed physically defensive
Politoed @ Leftovers
EVs: 252 HP / 252 Def / 4 SAtk
- Perish Song
Perish Song is great for forcing switches, and in some cases winning battles of you use it on the last remaining Pokemon of the opposing team. Protect is trolly and annoying,
and Scald is STAB and has a nifty burn chance. Toxic is rather obvious.
Forretress - Looks good, consider running Bold and having Volt Switch over Gyro Ball, provided you go from 4 Atk to 4 SAtk. Your call.
Toxicroak - I see you want to run a bully frog, and I have got just the thing for ya.
Toxicroak @ Black Sludge
Trait: Dry Skin
EVs: 252 HP / 252 Atk / 4 Def
- Bulk Up
- Drain Punch
- Suckerpunch/Ice Punch
Bulk Up makes your Substitutes difficult to break, and gives you a large offensive presence as well. Drain Punch is STAB and gets you even more recovery, while Suckerpunch is the preferred option for the last slot to hit Psychic types, but Ice Punch hits Gliscor, which kills T-Croak with relative ease.
Rotom-Wash - Everythung looks great on Rotom, just give him Pain Split over Signal Beam, as it can serve as recovery in addition to working well with your Life Orb.
Here is where I start to have problems with the team. Both Gorebyss and Eelektross are NU, and Gorebyss doesn't work in OU as anything but a Smashpasser, so I am going to replace him with...
Blissey - Simce Politoed is now your physical wall, this ugly pink thing will be tasked with absorbing special moves for you.
Blissey @ Leftovers
Trait: Natural Cure
EVs: 252 HP / 4 Def / 252 SDef
- Seismic Toss/Heal Bell
Now I realize it's taunt bait but it really helps the team by tanking special moves, healing the team's status (if you chose Heal Bell), and providing Wish support.
Eelektross is getting the boot for your new Choicer, and that Choicer is...
Thundurus-T - Thundurus-T supports your team very well with Volt Absorb and abusing STAB Thunder.
Thudurus-T @ Choice Scarf/Choice Specs
Trait: Volt Absorb
EVs: 252 SAtk / 4 SDef / 252 Spd
- Focus Blast
- Hidden Power [Ice]
- Volt Switch
Run a Scarf if you want him to be a deadly revenge killer and late game sweeper, and run Specs if you want to be easily revenged but possess the
offensive capabilities of an AC-130. I have used both variations of this set and both of them are lethal.
Focus Miss is coverage, HP Ice hits Dragons and Ground types, Thunder is STAB and hits Incredibly hard, and Volt Switch is good for scouting and revenge killing. If you go for the Scarf run Modest Nature, you go for Specs run Timid Nature.
Hope I helped!