If he fails, he loses his attack completely and can no longer even target Vitus. He may target anyone else, though, so if he has multiple attacks, he can take them against other people.
Since he moved 5 feet and then 'attacked', he can't move anymore.
Eeldai (djinni): moves out of the antimagic field. Is forced to save vs. the permanent Temporal Stasis as it reengages. The Dimensional Lock spell doesn't reengage, however.