idea for Athene's Unholy Grail

When your mana pool is practically empty, make it so you can never drop below 20 mana. Or if your mana drops below 20, get 20 mana over 5 seconds on top of the regen it offers. spells still cost full amount but will refund after using the spell. i understand it sort of does this. but not that much. the identity of athenes should be to always have mana for at least 1 spell. with brief delay until next spell.

this helps give the last 10% of your mana even greater returns.

i dont get why it scales off your mana, since the point of getting athenes is when you are not getting you can't spam quite as much but pretty close. i also miss the old passive:

UNIQUE PASSIVE: Increases your mana regeneration by 1% per 1% mana missing

rip ziggs mid lane. the nerf to athene's mr was sufficient the mana regen nerf destroyed ziggs.