Aribeth, Wavering Faithful

{w/b}{w/b}: Aribeth, Wavering Faithful becomes a
Human Elf Knight with base power and
toughness 5/4, first strike, vigilance, and lifelink.
{w/b}{b}{b}{t}: If Aribeth is a Knight, each opponent sacrifices a creature. Put two +1/+1 counters on Aribeth. Activate only if a creature you
controlled died this turn.