Self-mill and graveyard decks like Sidisi, Brood Tyrant or Hogaak, Arisen Necropolis are constantly looking for more cards that can provide value from the graveyard, so this fits the bill perfectly
Crabominables attack requires only 1 Energy and does 40 DMG in its first turn
In the extremely unusual case where the mana value of one or more of the targets changes while you're paying costs, the cost to cast Urgent Necropsy, including the additional cost, remains what you previously determined
This should make it so, more often than not, you can just accept the dialog without searching
Before Kaldheim released, Elves was close to being a competitive strategy
You can only activate mana abilities during spell casting when the game asks you to pay a mana cost