well, then u need to test it, you should 1 hit kill normal ongs to have a good leveling...
if you go light and fire nukes you wont be able to nuke all the time, so you'll need to see that you level ur ice nuke too till they do 1 hit kills (always 1 hit, not sometimes)
so 3 nukes with imbue would be enough, dont use shout, coz it wont help you that much coz ur 70:70... so my advise is, first lvl light nuke till you see its one hit.
prolly that will be on lvl 3 - 5 for u i guess.