Bad news: your bright yellow Gymno is a parasite on the green Hylocereus (the usual graft recipient). The Gymno is sucking the Hylo dry. The Hylo is trying its best to keep both alive. Its a hopeless case. The only outcome is death for the Hylo. You either have to re-graft the Gymno to a new recipent or call it a loss and start again with another blood sucking parasitic plant.
Daisy
