Q against laners you can burst/1v1
W if you're building tank/if you want a strong lvl 1-9. Purpose of this is to spam WW, push every lane to enemy tower, and slowly whittle their HP by using your heal to trade. I just tried this and it's actually pretty good, you still have some decent burst since WW has 340 base damage at level 9 and they typically won't build MR.
E if you want a safe lane phase/vs some ranged or low sustain tops, ie Elise where you just spam Bola to get them low, shove to their turret and dive.
E max gives you a pretty nice laning phase but generally you'll want to max Q. You want Q at rank 5 to burst, push and trade. The only real advantage to E max is that it allows you to harass safely during the early game.
This. The two top NA Rengar players, Ninfang and Dekar173, max different abilities first, with the former maxing Q and the latter E. Ninfang goes for a heavy snowball earlygame, while Dekar173 prefers to farm up to a monstrous lategame. I personally prefer maxing Q against melter laners due to its high damage output, but I'll max E against ranged champs who push me early.
W if you're building tank/if you want a strong lvl 1-9. Purpose of this is to spam WW, push every lane to enemy tower, and slowly whittle their HP by using your heal to trade. I just tried this and it's actually pretty good, you still have some decent burst since WW has 340 base damage at level 9 and they typically won't build MR.
E if you want a safe lane phase/vs some ranged or low sustain tops, ie Elise where you just spam Bola to get them low, shove to their turret and dive.