Steelix is a Stage 1 card so you would not necessarily have a stage advantage over your opponent, but heres how the combo worked:  Commander (CTRL to add secondary) Spark Double You may have this creature enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary
This means that by casting several spells, Hullbreaker Horror can be used to return several key cards to their owner's hand, setting opponents back to the Stone Age
This is a downside since you cant pay with mana and other resources
This allows any card from 1/16" thick (toploader sleeve) to 3/8" thick (magnetic one-touch holders) to slide downward to the inside of the front edge