What evidence is there for Mahakasyapa' s attainment of the four-fruit arhanhood, said to be one in escalation?
Chapter on Records of Conferment in Lotus Sutra has this to say:
Mahakasyapa, in future lifetimes, attains Buddhahood and is called the
Tathagata of Light, with Light and Virtue as his realm and Great
Adornment as his kalpa.