Ra is designed in a way that his abilities dont rely on mana. Hence his starting 10int, low int gain and low manapool.
Yet his ult is completely reliant on his mana. 3 hits of nullfire blade completely nullifies his ult, which honestly is just the worst feeling in the world.
Why cant ra's ult be independant of his mana situations? I actually dont think it would boost his winrate by too much, but at least 1 really annoying element would be removed.