The Mythic Heroes Handbook has an option for taking Mythic Arcane Discovery as a Mythic Feat, and one of the options for that is allowing the player/GM to create their own version of a mythic arcane discovery in addition to the simple numerical bonus so how would these forums design a mythic Arcane Discovery?
I'll get it started:
Mythic Creative Destruction: When casting an evocation spell you gain temporary hit points equal to 1.5 times the number of dice used to determine damage. When casting a spell of another school that deals damage you gain temporary hit points equal to the number of dice used to determine the damage. These temporary hit points do not stack with themselves and last for 24 hours.
Mythic True Name: You may add your tier to the maximum number of hit dice of the outsider whose True Name you discover. Alternatively, you may grant that outsider a mythic rank equal to 1/2 your tier.