mixedcards/Assets/Battle/Triggers/DamageTrigger.cs

using System.Collections.Generic;

public class DamageTrigger : Trigger {

    private List<BattleParticipant> observedParticipants;

    public DamageTrigger(List<BattleParticipant> observedParticipants, TriggeredEffect callback,
            TriggerExpiration expiration, TriggerRepetition repetition)
        : base(callback, expiration, repetition) {
        this.observedParticipants = observedParticipants;
    }

    public bool IsTriggeredBy(DealDamageEffect effect) {
        return effect.Amount > 0 && this.observedParticipants.Contains(effect.Target);
    }

    public bool IsTriggeredBy(MassDamageEffect effect) {
        if (effect.Amount <= 0) {
            return false;
        }

        foreach (BattleParticipant bp in this.observedParticipants) {
            if (bp.Team == effect.Team) {
                return true;
            }
        }
        
        return false;
    }
}