Lone Rider // It That Rides as One

Lone Rider's last ability triggers even if it wasn't on the battlefield when you gained the life this turn.

You must have gained life before your end step begins. Lone Rider's last ability won't trigger if you haven't, even if an ability triggering at the same time will cause you to gain life.

Lone Rider's ability checks how much life you've gained during the turn, not what your life total is compared to what it was when the turn began. For example, if you gained 4 life and then lost 7 life this turn, it still triggers.