Its not as impactful as a Craterhoof Behemoth, but its lieutenant ability can help you close out a game
Its strengths are very simple to grasp: It nets you a card, it is an instant, and there is a decent amount of flexibility in the way you cast it
Its not ideal in decks with smaller creatures, like Elves of Goblins, but more expensive creatures like Krakens, Leviathans, or Eldrazi will make exceptional use of this artifact
(2020-11-10) Krark's ability triggers at the same time as any other abilities that say "When you cast this spell" or similar, including cascade
The dossier treatment brings the skeuomorphic whimsy of a physical dossier to characters you'll see across Murders at Karlov Manor
The difference is that Zegana wants one creature to be as big as possible regardless of how many there are, while Tishana wants as many creatures as possible without caring how big they are