Senna needs a buff

She is slow both in movements and attacks. And getting attack speed items doesn't really solve the problem, because she needs to "charge" the relic cannon anyway. Her Q is weird - it requires a target in a close range, but hits AOE in a bigger area instead. Why does it require a target? This defeats the whole purpose of champion with scaling range if her Q essentially has 50% range. Her W is fine, although the time between enemy getting hit and it getting rooted is inconsistent. Her E is absolutely useless. It's a weak child of group-wide Akali shroud and Pyke E. You (and allies) get a very small movement speed buff and it "kinda" prevents enemies from using target spells on you. The problem is a long charge time (so you can't use it for disengage) and the fact that most good abilities (and especially CC ones) are AOE. Her R is mostly useless too. Yeah, it's global but it does 0 damage in a very narrow area and gives a weak shield to allies. Sure, keep a long cooldown, but it should deal more damage.