The Senna build for Support is Eclipse and Fleet Footwork. This LoL Senna guide for Support at Platinum+ on 13.23 includes runes, items, skill order, and counters.
Senna Counters
51.7%
(-0.2%)
63.6%
(-0.1%)
13.0%
(-1.2%)
13.5%
(-1.1%)
618
(-7)
