The trick with [glow=blue]Seaking H.A[/glow] is to get rid of [glow=red]Houndoom[/glow] first using another pokemon, then when [glow=orange]Machamp[/glow] comes in you let it kill your first pokemon (just so he doesn't use anything else but [glow=yellow]Thunder Punch[/glow] on seaking) then bring seaking, revive the other one just in case, build stacks up of spatk, and use [glow=pink]Agility[/glow] 3 times ( i think you can build 6 stacks of spatk so let machamp hit you with thunder punch 6 times) then you use [glow=blue]Surf[/glow] for the remaining pokemon .
Equip seaking with [glow=blue]Mystic water[/glow] just to make sure it 1 hit kills everything.
Ik it works I did it myself.