You have to copy your target seed, then go to the main window of RNG Reporter and change the method to Wondercard (5th gen). Paste your seed into the the main window where it says "Seed (hex)". Then, on the right of the main window there should be a button that says "Calculate initial PID RNG frame". Click it, and it will tell you the starting frame. Next click generate to generate the frames. Find the frame with your target IVs/nature.When doing wondercard seeds, RNGReporter shows how many frames there are, like 53, 55, whatnot. However, how many advances does that translate to? And it's the same as standard seeds, right?
(Using latest RNGReporter - 9.95, tried to catch flawless nonshiny event Victini.)
Advancements = Target Frame - Initial Frame
Make sure you're in a Pokemon Center with no moving NPCs.