({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 Cadric.