Patch 26.13 Senna Build
If you want to keep playing Senna and dodge her damage nerfs build this
Conditioning & Overgrowth make up for the lost tankiness while building full damage
I recommend even trying Attack Speed + Double Scaling HP shards. If not, AS/AF/HP or AS/MS/HP.
Why Senna soul rate adjustments are mostly cosmetic; nerf contextualization
Do 5 to 10 souls at 20 make or break the champion?
Whenever Senna bot gains any popularity and or strength the immediate reaction from Riot is to adjust her soul drop rate on minions she kills, and the community usually responds to the nerf as if it makes or breaks the champion, but what does it actually mean?
In patch 26.13 Riot is halving the rate from 10% to 5%, which on paper sounds massive, but what does the change mean once you quantify it?
If we assume Senna has 10cs/min, which is rare for the champion, especially in SoloQ, the nerf means that she gets 10 less souls at minute 20, which only really impacts her range thresholds and at best means -7.5 ad at minute 20.
People don't realize how little of Senna's total soul count actually comes from minions she farms, and how nerfs like this can literally be emulated through having a rough early game.
As for the other nerfs this is where you can argue that they hit Senna way more, especially worse Sennas that rely more on their Q healing, the shiv CD refund obviously hurts. The crit damage nerf only really starts impacting her current build of Shiv Cleaver Manamune/C44 at 2.5-3 items.
If you are willing to play a less safe, more damage oriented version of Senna, building items such as BotRK -> LDR, taking resolve to make up for the lost tankiness, you can essentially play the same champion next patch.
Senna guide with @CrownshotLoL soon.