({3} magic symbol) ({R} magic symbol) ({W} magic symbol) plus enough mana to pay for commander tax, if applicable available.
Steps
Cast
Gerrard either from your hand or from the command zone by paying ({2} magic symbol) ({R} magic symbol) ({W} magic symbol) and commander tax, if applicable.
Gerrard enters the battlefield, triggering
Cadric, causing you to pay ({1} magic symbol) to create a token copy of
Gerrard.
Activate
Phyrexian Altar by sacrificing the nontoken
Gerrard, adding one mana of any color.
Gerrard dies, triggering its ability.
Holding priority, activate
Phyrexian Altar by sacrificing the token
Gerrard, adding one mana of any color.
The token
Gerrard dies, returning the nontoken
Gerrard from your graveyard to the battlefield.
Repeat from step 2.
Resolve all
Gerrard triggers, exiling it if it's in your graveyard and returning all artifacts and creatures that were put into your graveyard this turn to the battlefield.
Results
Infinite blinking.
Infinite colored mana.
Infinite copies of all legendary creatures you control except