Absorbing Man and Titania

Damage doublers usually hedge in some direction: Gratuitous Violence caps its bonus to combat, Fiery Emancipation triples but taxes you six mana, and most others only touch red sources. This one doubles every point of damage any creature source you control deals, combat or otherwise, from any color of creature, at a rate cheaper than most of its predecessors. That "creature sources" clause is doing more work than it looks: it catches fight spells resolved through a creature, deathtouch pings, ability damage from the likes of Goblin Sharpshooter, and the punishment triggers on any creature that hits an opponent for taking damage. The 4/5 body matters because the effect wants a body attached to it, not sitting inert: it can swing behind its own doubler and turn marginal creature damage into lethal math a turn early. The tension the design lives inside is that a doubler on a creature is more fragile than one on an enchantment. An enchantment version shrugs off a creature-focused board wipe; a 4/5, however sturdy against a single removal spell, folds to the same sweeper that leaves an enchantment untouched. So the effect scales explosively but sits on a target that dies to the wraths a comparable enchantment ignores. What you buy for that risk is a repeatable, one-card scaling threat that treats a swing, a fight, and a tapped-down artifact creature's poke as equally worth multiplying.