It certainly has some explosive potential, but it seems relatively narrow. If I'm dedicating 4cc cards to a ramp strategy, the ramp effect needs to be pretty reliable for it to make the cut, and I think this may simply tap for C too often.
I think this is playable in a cube that supports storm and nowhere else. Any draw 7 effect makes this absurd (even without colored mana), but because it's so fragile and weak in a vacuum you really need to be powering out combo kills with her.
For a second I didn't see that tap symbol and got really excited thinking I got an increasing amount of mana free for each draw. This card however is meh, unless you are in commander cube.
Simic can use some love and this is an interesting ramp card. Memory Jar into Upheaval, anyone?
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Uril, the Miststalker RGW -- Ulamog, the Infinite Gyre C -- Vhati il-Dal BG -- Jor Kadeen, the Prevailer RW -- Animar, Soul of Elements URG
Kiki-Jiki, Mirror Breaker R -- Maga, Traitor to Mortals B -- Ghave, Guru of Spores BGW -- Sliver Hivelord WUBRG
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Maybe if you gained the mana when you drew or it was coloured mana, but maybe those would be too good because it would make cantrips free.
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Generals meant to be drafted first in a single pack of 6 cards.
And here is the actual cube, meant to be drafted in 4 regular sized packs. (60 card decks)