Core phantom was used to try to graverob Ekkos wish ability but it failed.
Dragon Fear makes him untargettable by the people he picks, he picked Ratchet and Ryu. He didnt want Ratchet to find out his role name and he used it on Ryu because the latter was suspecting him.
As for notable WUs between TACs death and the redirect:
This one is the most interesting imo.
Darkling is Arondight most certainly and he used something on something, was this one ever uncovered?