Samurott (Torrent)
-Surf
-Aqua Jet
/ Ice Beam / Return
-
X-Scissor
-Grass Knott
Mixed Set to take advantage of samurott's great attack and special attack
X-Scissor > Megahorn for the increased accuracy. You might want to use either Ice Beam or Return instead of Aqua Jet for more coverage.
Jolteon (Volt Absorb)
-thunderbolt
-Volt Switch
-Shadow Ball
-Signal Beam
Jolteon is probably one of my top 5 favorite pokemon

great movepool and supurb speed
Reuniclus (Magic Guard)
-Calm Mind
-Recover
-Psychic
-Shadow Ball
Despite his speed, reuniclus is such a deadly pokemon capable of taking down entire teams
Darmanitan (Sheer Force)
-Flare Blitz
-Earthquake
-
Rock Slide
-U-Turn
/ Fire Punch
If I need a pokemon gone fast, but i dont have a real answer to it, this is my go-to pokemon.
Zen Headbutt doesn't really do much for Darmanitan. Instead, go with Rock Slide for more coverage, and it also gets a Sheer Force boost. Fire Punch could work as your last move as a secondary STAB when you don't want to deal with Flare Blitz's recoil.
Mienshao (regenerator)
- Hi Jump Kick
-U-Turn
-Acrobatics
-Fake Out
I love mienshao mainly because hes a fast pokemon with u-turn making him an excellent scout.
Krookodile (moxie)
-Earthquake
-Crunch
-Rock Slide
-
Outrage / Dragon Claw
So much better than excadrill in-game. Capable of sweeping teams thanks to moxie. Edge-quake + crunch? Whats there not to like about this pokemon.
Superpower has almost identical coverage to Earthquake, and EQ is superior due to STAB and no negative side effects. Go with a Dragon type move instead.
Edit: If I were to add haxorus to the team, what pokemon should I take out?
Personally I think your team is fine as is, but Haxorus would play a similar role to Krookodile, running a similar moveset, so imo you might want to take out Krookodile if you add Haxorus.