Looking for a pokemon to carry me out of final battles

[fl_worldwide]

I would like any high level pokemon that fits in my team to help wining championship. My current team is:
Archilles
Gyarados 
S51-A
Tracton 
Fafninter
Baariette/ chimaconda 
Im willing to take out baar-chima just captured there (lol) and S-51 is weak as hell, simply can't kill anything. 
They're all around lvs 55 - 60, should battle more I know but I would like to skip this annoying as hell part, Ive been cross breeding with my brother and need the money to proceed. I got minicorn - eevee - devimp - dunsparce all with 4 IVS, or simple starter poks to trade. I don't know if this is exactly a deal cause they take time to train, but a boosted pokemon may level up very fast when in the championship, so I'm trying anyway. Thanks!

[Andyv2]

If you want to wreck the Championship, just level up a Nucleon to about level 60, teach it Hyper Voice and give it a Choice Scarf to hold. It out speeds and one shots most everything, bar Sheldon’s Steel type team, easily handled by Archilles.