Diana vs
Syndra

Syndra outranges you and pokes with Q whenever you step up. Play at max range and only engage when her E (Scatter the Weak) is on cooldown. You win when you get on top of her — she has no mobility.

Once you hit 6, any time her E is down is a kill. W in, Q+R+E and she dies or burns flash. Pre-6, an all-in at level 3 with ignite works if she is already low.

Shadowflame and Rabadon's are your core. Banshee's Veil can block her E stun. Mercury's Treads in extended teamfights.

["Her E stun requires a Q ball on the ground — if she has no balls placed she cannot stun","Approach from angles where her placed Q balls are not between you and her","Her R has a cast time — Zhonya's during the wind-up negates it","Post-level 9 with max Q, you delete her in one rotation"]