Standard cards use circle (Common), diamond (Uncommon), octagon (Rare), gold star (Super Rare), and silver star (Legendary)
Its controller searches their library for a basic land card, puts it onto the battlefield tapped with a stun counter on it, then shuffles
The average Commander deck will prioritize Eternal Witness and ways to recycle its ability before they ever even consider Den Protetor as a back-up, but morph decks can use it as a synergy piece and likely have ways to reuse its morph ability to pick up extra cards
Then each player who owns a spell you cast this way loses life equal to its mana value
Well once again be experiencing the story from the perspective of the five colleges of Lorehold, Prismari, Quandrix, Silverquill and Witherbloom
In multiplayer, that randomness keeps everyone on edge