Only opposing graveyards counting makes it much less reliable than the goyf though, although it helps that it still has 1 power when yards are empty, the non-scaling toughness has both good and bad moments, but probably mostly bad in situations where goyf would be worth including. It seems more like a semi-upgrade for Vampire Nighthawk than a 3 cmc black version of goyf.
Not crazy anymore, and 3 toughness is also hurting it to stay alive when you really need it (like against burn or swarming aggro decks).
On paper (and in limited for sure) this is kind of powerful.
Will see play for sure too, but relying on your opponent to play with you (and they not eating their grave with Uro or the like, reducing this back to 1/3) might not be a good recipe for constructed to guarantee this is actually as good as it might look.
In my book the Titans deliver a lot more punch for their bucks and its hard to beat them.