Also, the combo is fairly straight forward and uses as few as 2 cards, making it a good option for newer players
Graveyard commanders are a pretty broad topic: There are commanders that care about casting spells from graveyards, that let you cast spells from graveyards, reanimator commanders, discard commanders, self-mill commanders, and other ways to fill the graveyard if your strategy touches the graveyard, theres a commander for it
If you sacrifice an Island this way, Serendib Djinn deals 3 damage to you
Sadly for the little Splitter it rarely gets any play these days, not because it is too weak nor because it doesn't have homes
It notably triggers when a card is milled, not when you/an opponent mills, so anything that just dumps everyone's graveyards is fantastic here