Dragonic Overlord

Flying, vigilance, menace
Whenever Dragonic Overlord, attacks for the
first time each turn, untap all dragon creatures
you control. After this phase, there is an
additional combat phase.
{w}{b}{r}: Dragonic Overlord, gets Double strike
until the end of the turn.
"The dragon of apocalypse carved its name
into various annals of history."