Seeing as you need another legendary creature in play to take advantage of The Animus, this card will go best in decks that are stacked with a ton of legendary creatures that have powerful activated abilities or triggers
If I use X's ability to cast an instant or sorcery, does that spell go into my graveyard
I can see that strategy ending a game in your favor
Just take a look at Once and Future, Lucid Dreams, Rain of Revelation, Glimmer Bairn
The fact that it lets you sacrifice any permanent is great too, since it lets you make use of all the incidental artifact tokens we see these days
In the same manner that Sunfall had made a comeback due to the rise of control in Standard over the last few months, Split Up could serve as a good replacement