Éomer, Marshal of Rohan

The extra combat step has always been red's most reliable route to a lethal turn, and the ones worth building around invent a reason to earn it rather than just paying for it. This one asks for a sacrifice of sorts: the second combat arrives only after your own attacking legends die in the first. That is a strange knob to tie an untap-and-swing-again trigger to, and it points the card at a very specific board where legendary creatures dying mid-combat is a feature, not a cost. The untap clause is the part doing the heavy lifting; it refreshes tapped attackers, mana creatures, and anything with a tapped activated ability, so the reward is broader than a second alpha strike. Restricting the trigger to once each turn is what keeps it from spiraling into arbitrary combat loops with cheap recursion, the failure state a trigger like this invites. The self-referential wrinkle is that the ability keys off other attacking legends dying, so the marshal survives to lead both swings while his companions fuel the engine by falling. It is a payoff built for a deck full of legendary bodies, and the more of them that trade away in combat, the harder the follow-up hits.