This is an old favorite card of mine, when I had a legacy burn deck. I don't think it's great for Cube, though.
Generally speaking I think it's actually cool to have a few super-narrow cards, but I like them to play a defining role in deck archetypes. It can be really fun if you can change the way the game is played by just resolving a single spell. Sulfuric Vortex comes to mind. Vortex can play a really key role in burn and some aggro decks. Flame Rift I feel doesn't quite define a burn deck - it's just sorta one more card to help you hit critical mass. But, you can do almost as well with Searing Spear, a much more versatile card that plenty more drafters will be happy to see.
No two cubes are the same, and maybe Rift can be fun to include in your list ... but I would caution you that if you include a lot of cards that are super narrow and yet kinda replaceable, you might have a number of drafters ending up with piles of unsatisfying cards.
Generally speaking I think it's actually cool to have a few super-narrow cards, but I like them to play a defining role in deck archetypes. It can be really fun if you can change the way the game is played by just resolving a single spell. Sulfuric Vortex comes to mind. Vortex can play a really key role in burn and some aggro decks. Flame Rift I feel doesn't quite define a burn deck - it's just sorta one more card to help you hit critical mass. But, you can do almost as well with Searing Spear, a much more versatile card that plenty more drafters will be happy to see.
No two cubes are the same, and maybe Rift can be fun to include in your list ... but I would caution you that if you include a lot of cards that are super narrow and yet kinda replaceable, you might have a number of drafters ending up with piles of unsatisfying cards.