It has a strong ETB (we put a +1/+1 counter on each other Ally we control) and also synergizes well with our ETB and Blink strategies and can become a secret finisher as he gets +1/+1 on another Ally ETB and he has Trample, so on mass Blink he can become a huge threat
Heart of Kiran Heart of Kiran saw quite a bit of play when it was in Standard, and I could see it coming back again in the right deck
Necrogoyfs cost is a downside, but thats a problem with various low-cost solutions in a reanimator deck
If a card that's already been on the battlefield for a full turn becomes a copy of something else, it'll still be unaffected by summoning sickness
Its basically a Gaeas Cradle for Dinosaur typal strategies, with the added ability of letting your dead Dinos escape from the graveyard, assuming you have ways to fill it up with extra cards
It jumped from $9 to $17 this week, primarily driven by the new Quandrix Unlimited deck