Erstwhile Trooper

The activation cost is the whole strategic axis here: discarding a creature card to pump turns your hand into ammunition, which means this body wants a deck already overstuffed with creatures and ideally one that wants those discards going to the graveyard rather than into play. That is the quiet design logic. A 2/2 that swings as a 4/4 trampler is unremarkable on its own; what the once-per-turn discard does is hand the card a foot in two doors at once. It feeds graveyard-matters payoffs (reanimation, delirium, anything that counts creatures in the bin) while still presenting an honest, recurring combat threat that scales with how flooded your hand gets. The trample matters more than the +2/+2 in that context, since the discard most naturally happens in decks that play creatures you would rather have died than drawn. The once-each-turn clamp is what keeps the card from collapsing into a single explosive turn: you cannot dump four creatures to make a 10/10, so the pressure is incremental, a turn-by-turn conversion of excess cards into damage and graveyard fuel. It sits at the intersection of golgari attrition and aggro pressure without fully committing to either, which is both its appeal and the reason it tends to live in builds that already had a reason to be discarding creatures.