Senna is nice, but...
I am not complaining about her, no, in no event. But I feel like her attack speed is a bit too overnerfed. Don't make her like Graves. I think like you need to make some adjustments to make her a bit more fun to play.
Base stats
Range: 600 -> 500 (she's meant to have a weak early, right?) Attack Damage: 50 -> 44 (same reason as the above) Attack Speed: 0.200 -> 0.320 (still the lowest in game, but she deserves it buffed, on top of sacrificing the stuff at the top) Health at L1: 520 -> 500 (sure, why not)
Spells
Passive: Absolution Critical strike damage base: 130% -> 160% (I mean, she should still be a viable ADC, Yas has 100% crit in 2 items, but just -10% damage XD) Bonus AD per stack of Mist: 1 -> 1/1.33/1.66/2 (increased as she levels up her R) New bonus per 20 Mist stacks: Increases her health by 20 and life steal by 2%. Extra Crit to lifesteal: 35% -> 20%
Q: Piercing Darkness Damage: 50/80/110/140/170 (+50% bonus AD) -> 60/80/100/120/140 (+45% bonus AD) (+1.2 per 1 Mist collected) Cost: 70/80/90/100/110 -> 90 mana at all ranks Heal: 40/60/80/100/120 (+40% bonus AD) (+25% AP) /OwO/ -> 32/44/56/68/80 (+45% total AD) (AP removed, why the f even keep it?)
R: Dawning Shadow Damage: 250/375/500 (+100% bonus AD) (+40% AP) -> 125/200/275 (+70% bonus AD) (+5 per 1 Mist stack) Shield: 120/160/200 (+40% AP) (+1.5 per 1 Mist stack) -> 80/115/150 (+2.5 per 1 Mist stack)
I am writing this because I think it will make her more interesting to play. Please let me know if you like these changes. Adding the amount of Mist stacks in more places will emphasise on how much she needs them and will make players aim to collect as much as possible. Thought it was an interesting concept :)