Spells are good cause, exhaust is great skill with catching and running and with that mastery it reduces mr and ar, fortify is good for ur Q skill= rocket grab u can pull ur enemy to ur turret, put fortify on and knock him up with E skill= power fist, im sure that makes some dmg :D

manamune is important for gaining ad and mana & manaregen, trinity maybe best item for blitz, i buy mercurys casue i get much ar from other items so i need mr and movement speed is gained from trinity, frozen hart is good item for ar and mana for gaining ad from manamune also it reducest movement and attack speed from nearby enemys and u get bonus for blitz passive, warmog is for health, and last item atmas impaler is for dmg from warmog, so im pretty sure u will get kills and assists with this build, depending ur playing skills ofc :D

dont be shy with ur ultimate it have small cd so use it to big groups of minions

ps. remember to vote