Finally.[/b] After redoing the same battle
five times and redoing the portion after that
four, I just got done with the gold thief. His behavior is exactly the same as the silver thief's, so the exact same strategy was used, but some additional dodges were incorporated. I got him to dodge twice in a row at the end, but unfortunately I can't get the same effect at the beginning, so I let him rough me up a bit like his silver cousin.
It came nearly a week later than anticipated, but here's the WIP as promised:
http://www.filespace.org/Hermbletont/Wizards_n_Warriors_3_WIP.fcm . I ended it on frame 24816 (my last one was integers, so now I did powers of two <^_^>).
After some testing, I noticed that skipping a level will give you the previous level as well, so I can get the barrier without having to do the trial. Useless, but interesting nonetheless.
Edit: I have no clue what I just did, but somehow I fell right through the floor.