League of Legends (LoL) Question: Senna adc or support

I personally think she's a better support, for the fact that you can have an ADC + Senna in lane and not have a problem. You have much more power in lane

its an ADC. BASICALLY which hero has more damage ability is adc and which has ability to shield, heal , stun or crowd control is mainly for support role. HOPE this will help you.

ADC is stronger right now, though Riot has plans to nerf her for ADC and buff her for support by tweaking her passive. You can play her support in some matchups but I'd say ADC is better right now.