My name is deathbat I am a bronze 2 support-top main focussing mainly on mage supports and senna but also play a bit of blitzcrank and top laners like Darius, Mundo, mordekaiser, and wukong. I have Mastery 7 with 54k mastery points on senna so I consider myself a bit of a senna fanatic staying up to date on the latest builds to test in game.

Senna is a very strong champion no matter what stage of the game you are in. She has one of the highest auto attack ranges level one at a ***ping 600 base attack range on par with Anivia and Ashe and beaten by Aphelios, Caitlyn, and Annie. Due to this you will want to abuse it level one taking heavy auto Q trades with the enemy adc and support keeping them off the wave, allowing you to get souls for your passive, and allowing you and your ADC to hit 2 first. Speaking of souls from her passive this is a core part of what makes her strong. Senna's passive gives her 0.75 bonus AD per soul and for every 20 souls she collects she gets 20 attack range(uncapped) and 10% crit chance(capped at 100%) after getting 100% crit or buying rageblade she gains life steal instead of crit. Her main combo is Auto-Q or Auto-Q-Auto which allows you to inflict an enemy with your passive and collect the soul. You will also want to be fishing with your W root which can lead to all ins with your ADC.

After laning phase you will want to stay near your team especially when the are farming to maximize soul drop rates whether that be from lane creeps or jungle camps. Your goal as senna is to DPS from the back line all while healing your allies and ulting if getting caught. Use your E to speed up allies when sieging and save your W for when someone tries to enter your backline.