Electra, Fist of Rhalgar

Double strike, Haste, Trample
You may cast Electra, Fist of Rhalgar during
combat on your turn. If you do, Electra enters
the battlefield tapped and attacking.
{x}{r/w}: Electra, Rhalgar's Fist gets +X/+0 until
end of turn.
From knowledge strength, and from strength, service.