This is a low-cost, sustainable form of card advantage that works great with many Crimson Vow vampires
It's very strong in 20-life formats where you can get the 4/4 flying Dragon over time and then remove things as you cast more and more instants and sorceries
She encourages us to make our Magnemites unique and give them personalities
The thing is, it has far worse specific card quality than the black Tutors, most of the time in cube you just want general card quality, the need for finding specific things is dwindling
The cards efficiency drops considerably when targeting one or two mana spells, which has made EEs prevalency in Modern very dependent on the metagame
Here's some quick links to keep you on top of the situation, just bear in mind that the pricing will almost certainly be above MSRP and in-line with current market values: What's inside Phantasmal Flames products