You got an adamant Arcanine, so you can take it 2 different ways with its EV spread from the typical 252 in ATK and SPD with 4 going into DEF/SP.DEF
or you can go 252 in HP and ATK with 4 EV's into SP.DEF
Items to give your Arcanine, that depends on you if you want to take it to the competitive scene, from Leftovers/Assault Vest/Boots/Life Orb (this one i suggest you don't unless you play lower on the ladder but is better on Hisuain Arcanine)
I wasn´t asking for advice. This was that distributed shiny Arcanine, that someone used to win a tournament i guess.
I commented on how weirdly the stats are distributed. circa 240 HP, 84 Attack, 96 Defense, 76 Speed and 12 Special Defense.
This is some highly specialized shit, probably calculated so it survives a specific attack from a specific mon, outspeeds whatever it needs to outspeed, and barely K.O.s what it needs to.