I'll explain it. The summons mystery skill function gives select summons mystery skills that are activated by the MC's mystery skill and all are unique to each summon. pakun will attack all enemies on a team in a 1v1 battle, shiba will be summoned into battle, monkey and gamachu boost stats, giant katsuyu heals the team and monkey king summons clones of the MC. There will also be summon stones to unlock the mystery and upgrade it and the stones will be unique to each colored summon.