You can use Arven to get two of your most important cards, Vitality Band and Vengeful Punch. If one of your pokemon is KOd, then Vengeful Punch does enough damage to setup your Kingambit. However, your main strategy is to attach a Vitality Band to deal 40 damage which lets Kingambit attack and also increases the prizes you take by two so with one attack, you'll get 3 or 4 prizesand they can't even retreat since Kingambit can hit anything. Other notable cards include Radiant Alakazam which can move damage counters which might let you take out something that doesn'tt already have enough damage on them and one copy of Mismagius which can deal damage to all of your opponents Pokemon which means you can kill them after two attacks or more easily get them to 4 damage with Alakazam.