Are you trying to say that the databases wouldn't come up or that you just didn't understand them? Because Normal Fusions are extremely simple. In the Fusion Database, he has a listing that tells you which two Arcana make a specific Arcana when fused together. So, for example, if it says desired result Temperance with two of the choices being Magician and Chariot, just fuse those together to get the one you want. Mithra is around level 22, so you would need two Persona that are around those levels to end up with Mithra. Triangle Fusions I find annoying since the highest leveled Persona matters and such, but still easy to figure out with a little cross referencing in the FAQ.