first of all ...
TRAIN IM IN ATK !!!
second of all I never did train Pokemon in ev but I know enough about Pokemon in general to tell you ...
TRAIN IM IN ATK !!!
with that said here goes the technical aspect
SLAKING
![slaking][1]
he is know to be THE Pokemon with the highest stats of all none legendary Pokemon (and I wanna precise he got even higher stats than some legendary and all pseudo lendary Pokemon) and he is THE Pokemon with the highest atk base stats of all time excepted from black kyurem
but ... he has truant ... good way to break the party there gamefreak ... thanks
now to talk about statistic and strategies here is what I recomend for you
slaking
EVS : atk MAX OUT,hp MAX OUT ... yeah I dont know what are the number of a evs maximise stat so ... atk MAX OUT , hp MAX OUT !!!
ABILITY : the rival of defaitist for the WORST ABILITY OF ALL TIME ... truant ... the raison why you want hp evs cause this way you can last longer in battle cause ... your gonna take free hits ... nothing else to say so ... next
MOVE SET
GIGA IMPACT : kinda deal with the frustration of truant ... kinda
BRICK BREAK : just in case you want to deal with things like light screen , reflect and such while doing A LOT of dammage thanks to slacking atk
REST : you got lots of hp and your obligated to do nothing 1 of each 2 turn then why not take a good rest to recover while your at it ?
EARTHQUAKE : TO DESTROY EVERYTHING IN YOUR WAY ... except flying type or levitating oponent ... BUT TO DESTROY EVERYTHING ELSE IN YOUR WAY
so ... yeah TRAIN IM IN ATK !!! ... he is made to destroy thing with brutal force.
[1]: http://img.pokemondb.net/sprites/black-white/anim/normal/slaking.gif