Rider Alpha, Genocide Beast

Devour 2
{b/g}{b/r}{b}: Target creature gets -1/-1 until end of turn. Rider Alpha, Genocide Beast gets +1/+1 until end of turn.
Partner. If you control another Elemental Soldier creature you gain "{2}{b}{b}{b}, {t}, Exert Rider Alpha, Genocide Beast: Put a -1/-1 counter on each creature opponents control
and a +1/+1 counter on Rider Alpha for each counter placed this way."