You control at least one additional creature that does not have summoning sickness.
An opponent cannot block creatures you control.
Steps
Declare Warcry Phoenix, Grand Warlord Radha and at least one other creature as attackers.
Grand Warlord Radha and Phoenix Chick trigger.
Resolve the Grand Warlord Radha trigger, adding at least ({R} magic symbol) ({R} magic symbol) ({RG} magic symbol) .
Resolve the Phoenix Chick trigger, causing you to pay ({R} magic symbol) ({R} magic symbol) to return it from your graveyard to the battlefield tapped and attacking with a +1/+1 counter on it.
Deal combat damage using Warcry Phoenix.
Breath of Fury triggers, causing you to sacrifice Warcry Phoenix, then attach Breath of Fury to Phoenix Chick, then causing you to untap all creatures you control and to get an additional combat phase after this one.
Move to your next combat phase.
Declare Phoenix Chick, Grand Warlord Radha and at least one other creature as attackers.
Grand Warlord Radha and Warcry Phoenix trigger.
Resolve the Grand Warlord Radha trigger, adding at least ({R} magic symbol) ({RG} magic symbol) ({RG} magic symbol) .
Resolve the Warcry Phoenix trigger, causing you to pay ({2} magic symbol) ({R} magic symbol) to return it from your graveyard to the battlefield tapped and attacking.
Deal combat damage using Phoenix Chick.
Breath of Fury triggers, causing you to sacrifice Phoenix Chick, then attach Breath of Fury to Warcry Phoenix, then causing you to untap all creatures you control and to get an additional combat phase after this one.