Humans can't be mutated onto. I see you have
blighted agent,
Fynn the fangbearer, Thorn of the blackrose in there. I'd swap the
blighted agent for
glistener elf (since Brokkos has trample already). The other two are decent additions despite not being mutate targets for Brokkos due to Fynn's ability gelling with the rest of the deck and the Thorn's ETB for monarch.