Pattern of Rebirth - Just another one of those effects I like to think about when playing a green based sac deck. Setting up a creature with this and then end of opponents turns whipping an eldrazi to play sounds kinda great too.
Skullclamp - Well, it goes well with sort of what you are doing.
Invasion of Ikoria - I did some thinking about
Unmarked Grave and came to the consensus that you are probably better served by this card given its sort of the same mana to set up but its a creature to play rather than grave. I almost tried justifying this suggestion being
Heirloom Blade because I think it would be funny to do it to get gravecrawler but I just couldn't really bring myself to even entertain that being a better idea than the battle lol.