Piston-Fist Cyclops

A 4/3 for three mana is aggressively costed for the body alone; the defender is the toll, and casting an instant or sorcery this turn pays it. That conditional turns a wall into a beater for the cost of doing something you were already inclined to do in a deck full of cantrips and burn, which is the design's whole pitch: reward the spellslinging archetype that struggles to find a creature worth the slot. The toggle resets each turn, so attack permission is a recurring check the deck has to pass rather than a one-time unlock, keeping the body honest against opponents who can strip your spells or race you on the turns you keep mana up for interaction. It sits in a lineage of creatures whose ability to attack is gated on noncreature-spell activity, the prowess-adjacent space where a cheap body asks the spell-heavy deck to keep doing what it does and converts that activity into pressure. The cleaner the body, the sharper the tension: a 4/3 clocks fast enough that the deck genuinely wants to attack, but the defender clause means a turn spent only developing or holding up countermagic leaves the Cyclops standing still. The card is most itself in the deck that never wants to stop casting spells anyway.