Add guards and implement basic cards

Assets/Battle/CardsHeroes/SmokeBombHCard.cs

@@ -0,0 +1,19 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class SmokeBombHCard : HeroCard
+{
+    public SmokeBombHCard(BattleParticipant owner)
+        : base(owner, HCardId.SmokeBomb, "Smoke Bomb", 2, CardType.Skill,
+            "Blocks 2 damage on all allies.") {
+
+    }
+
+    public override IEnumerator Use(IBattleEffectApplier effectApplier,
+            MonsterViewpoint viewpoint, BattlePlayerControls playerControls) {
+        yield return new WaitForSeconds(0.8f);
+        effectApplier.Apply(new MassBlockEffect(TeamChoice.Heroes, 2));
+        yield return new WaitForSeconds(0.8f);
+    }
+}