An opponent is unable to block and kill Rapacious One.
Steps
Deal combat damage to an opponent with Rapacious One.
Rapacious One triggers, creating five 0/1 Eldrazi Spawn creature tokens.
Move to your postcombat main phase.
Activate Phyrexian Altar five times by sacrificing the five Eldrazi Spawn, adding ({3} magic symbol) ({R} magic symbol) ({R} magic symbol) .
Activate Aggravated Assault by paying ({3} magic symbol) ({R} magic symbol) ({R} magic symbol) , untapping all creatures you control and causing you to get an additional combat and main phase after this one.