Elemental Mascot

The 1/4 flyer with vigilance is the tell here: this is a body built to survive the game it wants to play, not to end it early. Opus gives it two gears. The base mode is a pump-per-cast that turns a defensive blocker into a slow clock as you chain spells, but the interesting clause is the mana threshold. Spend five or more on any single instant or sorcery and you exile the top of your library to play through your next turn, converting a big-mana spell into card advantage on top of whatever that spell already did. That threshold is the design discipline: the pump is free on every cantrip and bolt, but the impulse draw asks you to be actually casting expensive things, which biases the card toward a spell-heavy midrange shell rather than a one-mana burn deck that would happily use the +1/+0 and nothing else. The vigilance matters more than it looks, since it lets the creature keep attacking into the pump while still holding back a wall of a toughness for the turns you have no gas. What the card is reaching for is the payoff-that-blocks: a spellcaster reward that does not fold to the first attacker while you wait to hit the mana it wants, and that scales cleanly with how top-heavy your instants and sorceries get.