Its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle
Covenant is also a fine sweeper-style effect in a multicolor control deck, with many EDHREC users slotting it into decks playing mana creatrues, counterspells, and other staples like Rhystic StudyRhystic Study, Esper SentinelEsper Sentinel, and Cyclonic RiftCyclonic Rift
Yarus, Roar of the Old Gods I concern myself primarily with the card drawing effect on Yarus, Roar of the Old Gods and it's OK
But the things that actually separate a proxy that feels like a card from one that clearly does not, those details live a level deeper than the artwork
From there, The Spear offers some flexibility, but none of the modes available are that exciting
We're just happy that getting such a combo in operating order is pretty mana intensive