Mentor's Guidance

In Commander, Mentor's Guidance earns its slot in any deck that routinely casts two or more spells per turn — it converts a normal spellslinger turn into instant-speed card advantage that refuels your hand before opponents can react. In Legacy and Vintage, the competition from Brainstorm, Ponder, and Treasure Cruise is simply too steep; Mentor's Guidance doesn't make the cut in those formats regardless of how many spells you chain. Modern and Pioneer are similarly hostile to three-mana draw spells without guaranteed card parity, so outside of niche spell-count brews it rarely sees play. Commander is where Mentor's Guidance actually lives — the longer game, the spell-dense strategies, and the lack of format staples that outclass it all conspire to make it a legitimate inclusion.