Whenever you cast an instant or sorcery spell with mana value 3 or greater, roll a d20.
1-9 | Each player draws a card.
10-19 | You draw a card.
20 | Copy that spell. You may choose new targets for the copy.
Mathise is a mono-blue spellslinger commander that wants you to chain expensive (MV 3+) instants and sorceries, rolling a d20 each time for card advantage and the occasional free copy. You play a draw-go control game—counter threats, draw cards, and ramp toward big spells—then close with a high-impact finisher that the d20 might double on a natural 20. Most of your value comes from the 10-19 'you draw a card' band, so casting many qualifying spells snowballs your hand.
Generates consistent card advantage on every big spell, even on bad rolls (worst case everyone draws).
Mono-blue gives access to the format's best counterspells, card draw, and tutors for consistency.
The natural-20 copy can swing games by doubling an X-spell, board wipe, or extra-turn spell.
Low cost (3 MV) and naturally protected by counter-heavy blue shells.
Mono-blue lacks efficient removal and can't easily clear resolved permanents or big boards.
Dice variance—the 1-9 band hands opponents cards, occasionally helping them more than you.
No inherent way to convert card advantage into a win; needs dedicated finishers.
Vulnerable to fast aggro and creature-based strategies while durdling on instants/sorceries.
The premier mono-blue board reset that triggers Mathise and is backbreaking if copied on a 20.
Lean into low-cost card-advantage engines (Mystic Remora, Rhystic Study) and efficient ramp (Sol Ring, mana rocks, High Tide) so you can cast multiple triggers per turn. Add scalable X-draw spells and copy enablers, plus blue tutors like Mystical Tutor and Long-Term Plans to find your finisher. To raise power, build toward a compact combo—infinite mana plus an X-draw to deck the table—while keeping a dense counterspell suite to protect it.