Whenever a creature you control attacks, Hellrider deals 1 damage to defending player.
3/14/2017 The damage dealt by Hellrider’s triggered ability isn’t combat damage and may be redirected to a planeswalker controlled by the defending player.
3/14/2017 If a creature you control attacks a planeswalker, the defending player is the controller of that planeswalker.
3/14/2017 In some multiplayer variants, creatures you control may attack multiple players and/or planeswalkers. For each attacking creature, Hellrider will deal damage to the corresponding defending player.