Mythic/Ascendency Tab

[xWhiteGodx]

Is it possible to create a Mythic tab or Ascendancy tab so that I can let my PCs (and myself) add in crazy buffs/boons? While Epic Boons are nice in 5e, I think a Mythic (or ascendant) tab should be added. Reason being is so that crazy things like

Ascension of Spell Immunity
You are immune to the effects of 1st through 3rd level spells.

I know customers can't add tabs, which is a bit unfortunate when it comes to adding in further customization, but is the possibility existent to add in something of the like, or does it have to exist core 5e?

Additionally, is it possible to have an option to remove the cap of 30 for ability scores for DMs and PCs that want to play against Gods? It doesn't make much sense that a God would have, say, a STR of 30 when there are ancient dragons with 30 STR as well.