Rell Build Guide by The_Brainstorm

Hi! I'm a rell noob so this might be a super dumb question. What do you think about nashors tooth? As third item or so depending on need? I was thinking the attack speed could help both with stacking your passive on multiple targets and with activating phase rush quicker, while the 100 AP would be a nice damage buff for things like Q and R (and the on-hit damage is a nice bonus). I have mainly just tried Rell as a support but I feel like she is a bit lacking in damage. If I engage and they stun my DPS I feel like I have exactly 0 impact on their hp bar without them. I've tried it out in practice tool and I do think it's nice but I thought I'd ask for an extra opinion before building it in game ^^