pokemon japanese vstar universe booster box [JP] This special set from the Sword Pokemon Japanese VSTAR Universe Booster

Also, Dogmeat, Ever Loyal produces a Junk artifact token whenever a creature you control that is enchanted or equipped attacks

From a small sample, Lightning and Psychic Energy appeared the most often (in Gym Heroes it was Lightning Energy, Gym Challenge I did not look at)

R Rare Mooyan Curry X SPELL Choose 1 player

C Common Melffy Wally X EARTH Level 2 [ BeastEffect ] ATK 0 DEF 400 If your opponent Normal or Special Summons a monster(s) (except during the Damage Step), or if an opponent's monster targets this card for an attack: You can return this card to the hand, then you can Special Summon 2 "Melffy" monsters from your Deck with different names from each other, except "Melffy Wally"

There are a couple of ways to do this