I've played against, and as, Senna. I can say that, although her kit seems fine, her numbers are a bit high, in my opinion. I think some nerfs should balance her out and put her in a good spot. My suggestions are:
- Decrease her base range to 500. Right now, her 600 range makes her a lot safe. This is problematic, considering how easy she can out poke her opponents with her Q, while also sustaining her lane.
- Decrease her basic attack wind-up by a little bit. Atm, she attacks way too fast for how slow she's supposed to attack.
- Killing Mist Wraiths should only reward 1g, at best, if not none. She should not get free gold, considering her cheap build paths (AD and AP).
- Increase the stacks threshold to 30, or even 35, for each stats boost. Right now, she scales way too fast in the early game and she deals too much dmg, because of it, considering how early it is in the game.
- **Q**: Remove the AD scaling on the healing part (+40% bAD > +0% bAD) or decrease it to +25% bAD, at best. Increase her AP scaling from +25% AP to +30% AP. Her healing shouldn't scale with AD, it doesn't make any sense. Let the healing scale with AP and the damage with AD. This will push players into building differently depending on whether they go ADC Senna or support Senna. Why would she heal more when she's ADC than when she's Support?! It makes no sense. Right now, she offers more in terms of utility and damage when she's built AD. Her AP builds are almost non-existent.
- **W** is fine.
- Decrease **E**'s duration from: 6 to 8 sec > 5 to 7 sec.
- **R**: Remove the AP scaling from the damage part of it (+40% AP > 0% AP). Increase the AP scaling on the shield from +40% AP to 50% AP. Also, let only the central beam grant **Sight**. As a jungle main, I find it stupid to be revealed in the jungle by this wild and huge beam, when it wasn't even directed at me. Just make the side beams only shields but don't grant **Sight**. Let the central, damaging, beam grant that instead.