Activate Korozda Guildmage's second ability by paying ({2} magic symbol) ({B} magic symbol) ({G} magic symbol) and sacrificing Brokkos.
When Brokkos dies, Pitiless Plunderer triggers, creating a Treasure token.
Resolve the Korozda Guildmage ability, creating six 1/1 Saproling creature tokens.
Activate Phyrexian Altar by sacrificing a Saproling, adding ({1} magic symbol) .
When the Saproling dies, Pitiless Plunderer triggers, creating a Treasure token.
Repeat from step 1 three additional times.
Activate five Treasures by tapping and sacrificing them, adding ({UB} magic symbol) ({B} magic symbol) ({G} magic symbol) ({G} magic symbol) ({G} magic symbol) .
Cast Brokkos from your graveyard for its mutate ability by paying ({2} magic symbol) ({UB} magic symbol) ({G} magic symbol) ({G} magic symbol) , putting it on top of a Saproling token.