Freyalise promised a dawn that would never end, a day of limitless life. As many dread her promise as revere it.

Upwelling

Players don't lose unspent mana as steps and phases end.

Tenth Edition

Mana pools don't empty at the end of phases or turns.

Once again, Kamahl felt the full force of the Mirari's pull, but he had learned much since the last time.

Scourge

Mana pools don't empty at the end of phases or turns. (This effect stops mana burn.)

Players can keep unspent mana indefinitely while this is on the battlefield, but once it leaves the battlefield, they have until the end of the current step (or phase) to use the mana before it disappears.