New Mage Playstyle

So, so far we have Mage that uses mana but also at times they regenerates mana on their item and runes. But what if Riot make _A NEW CHAMPION _ that could store mana, but cannot regenrate mana by item nor rune, only through other champion and at their base. In other word, He/she can't produce mana through anyway but can either steal or get it from base. What do you think about that guys?