It's not quite Primeval Titan, but it has the benefits of being Commander legal and doubling up on your Lotus Cobra and Omnath, Locus of the Roil/Omnath, Locus of Creation triggers
Irencrag Feat provides a huge leap in mana, but it locks you into casting only one more spell that turn
Overlap the corners of the cards so that they intertwine with each other
In fact, Landfall is one of the most popular builds of Yarok, providing value ramp to ensure you can keep replaying the Elemental Horror even if they deal with it
Mixed with the right creatures, it can be the heart of a powerful combo deck: Yawgmoth, Thran Physician, plus two undying creatures (for example Geralfs Messenger and Young Wolf) generates a Yawgmoths Bargain sort-of engine, that can be turned to a One Turn Kill adding a Zulaport Cutthroat effect to the mix