Here are some ideas cribbed from a game that does "epic" content better
Benefit: Choose a school of magic you already have Spell Focus in. The bonus to save DCs provided by Spell Focus and Greater Spell Focus for that school increases by 1.
Select one school of magic. All bonuses from your feats andmythic featsenhancements that apply to another school of magic, such as Spell Focus feat and School Specializationmythic feat, now apply to the chosen school of magic too.
Ascendant Element You mastered a certain element to spectacular level.
Benefit: Choose one energy type (acid, cold, electricity, fire, sonic, or negative). The damage of that energy type you deal can no longer be prevented or reduced by resistances or immunities.
Elemental Barrage You mastered the art of raining elemental spells on your foes, and found a way to empower them by combining different elements.
Benefit: Every time you deal energy damage to a creature, you apply an elemental mark to it. If during the next three rounds you deal energy damage to a marked target with a different type of energy, the target is dealt additional untyped damage.
I'd love feats that are thought out well and build upon each other and enhancement trees etc.
But does anyone ever see SSG coding any of that. And even then, coding that successfully?
I went as basic as possible.