Você não precisa trocá-los, basta ir até a quest Lemon Shop no modo normal do epi 2, na primeira sala está Paganini, ele pode trocar as photon sphere por photon drops.
actually is kinda the same time doing with df wave, i tried tempest and burning gun and make the same effect but time still not great, but still need to try combo weak attack gun to see if works good, im making some test in others weps tho