This mechanic means, "When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less
This card is just very efficient, very good, and can provide many two-for-one exchanges
I suspect this will soon also get cut as low power general purpose cards need to see play in more than one broad archetype to deserve a cube slot
It doesnt get any more one-sided than Ruinous Ultimatum, unless, of course, you play Cyclonic Rift
It is pretty hard to miss with this, you know what you want to hit and what colours they are, often even what is the main colour and which the splash
A general piece of advice is to aim for a smooth distribution of cards from each ink cost, ensuring you can consistently use all of your ink to affect the board in the early turns