I am afraid I have found no record of Ioallis ever having been used as a name in the Hellenic world. Of course that doesnt mean I cannot concoct an etymology for you (hehe). Ioallis -- the "o" written as an omega -- may be related to the ancient Greek exclamation "Ioa!" which was a precusor of "yo!"(Henry George Liddell, RobertScott, A Greek-English Lexicon). In this sense, "Ioallis" in Classical Greek could have meant something along the lines of "soul sista".