item: chesto berry
Air slash - STAB, only attack, flinch
substitute - To last longer, and it's annoying with rest
Rest - Recover hp from substitute
Double team - high evasion, higher annoyance!
So, first you use substitute then double team and just repeat until you have to use rest. After you believe you have high enough evasion you just keep attacking with air slash.
Although this moveset isn't practical, if it works out well it becomes very annoying for the other player.