Removing a creature is pretty potent, so the design team decided to make it a one-time thing and turned it into an enters-the-battlefield trigger
Understanding the price curve Graded card pricing follows an exponential curve, not a linear one
A proxy is used when a collectible card game player does not own a card, and it would be impractical for such purposes to acquire the card
Four mana isnt a ton and makes this more efficient than most of the other tutors unless youre specifically looking for a 1- or 2-mana spell, and even then, its on par with Chord and Finale
If you had to put together a list of your top 10 assassins in Magic and what characters you'd pair with those cards, I'm sure your list would look very different from my list, but that's the fun of a list like this
Efficient Deck Storage Box Solution: The Black Bolt Card Holder Case is compatible with Yu-Gi-Oh