Yidhra moves extremely fast but cannot hit or chair survivors. She is invisible, though survivors within 20 meters receive a notification icon. Follower (External Trait): Yidhra starts with one Spawn Follower that follows her and cannot be removed. She can also

You spawn leech marks on the ground. But you can also spawn them under a Survivor's feet if you switch to Yidhra and tap the ability while they are decoding. Use this to infect a Survivor without them stepping on a mark. They will only realize they are infected when you summon the Follower behind them.