Ancient Copper Dragon | Illustration by Antonio Jose Manzanedo Red cards, for our purposes, are any card whose color is exactly red
Cards with prowess, or cards that provide +1/+1 counters whenever you cast an instant or sorcery are perfect fits within a spells matter Wizard shell
Their trigger reads, Whenever a land enters the battlefield under your control, you may gain control of target creature for as long as you control Roil Elemental. So, basically, as long as you can keep Roil Elemental alive, you can absolutely steal every other Creature on the battlefield
Cards will naturally fall into your graveyard over the course of a game, but theres no reason not to hurry the process along a little with interactive cards like Swallowed by Leviathan
With some self mill and an empty board, you can gain a good amount of value
Abolish is happy to take one of them off your hands to destroy a problematic artifact or enchantment