Does the talent learned affect the token received?
From training your pet to Mega, you receive 2 tokens. The first seems to be either the pet's school or school triad (elemental/spiritual), but from my last two pets trained to Mega it seems that the second token is based the talent learned.
Trained my Death Ghulture to Mega and it learned Stun Resilient (rip); I received a Spirit Token and Myth Token.
Trained my Death Ghulture to Mega and it learned Plague; I received a Spirit Token and Death Token.