Priest T6 Bonuses

[Skandranon]

Also he can play interesting mana regen games with the 5 second rule. If two crit in a row then he's probably into high regen so he can pause the next heal or Divine Favour it to keep his regen going

Not true. Illumination doesn't actually make your spell free, it just refunds the full mana cost after it crits. Which is to say, you cast it, the cast completes, you lose mana, then you gain mana back if you crit. Paladins are inside the 5 second rule constantly.