2022-02-18If a channel ability requires a target, you may not activate it without a target just to discard the card.
2022-02-18Discarding the card is part of the cost to activate a channel ability.
2022-02-18If a player casts a spell that targets multiple permanents their opponent controls with ward, each of those ward abilities will trigger. If that player doesn't pay for all of them, the spell will be countered.