Commanders you control have menace and deathtouch.
Partner (You can have two commanders if both have partner.)
Falthis is a support partner who turns your other commander into a hard-to-block, hard-to-trade-with threat by granting menace and deathtouch. You pick an aggressive partner, suit it up with evasion and pump, and grind out commander damage while deathtouch makes every block a disaster for opponents. Play to the board early, protect your attacker, and close with 21 commander damage or a wide aggressive swing.
Deathtouch + menace makes your partner attack profitably almost every turn
Menace forces two blockers, deathtouch makes those blocks lethal trades
Cheap at 3 mana and flexible thanks to Partner
Enables fast commander-damage kills with the right partner
Does almost nothing on its own without a partner to buff
Mono-black color identity limits removal/protection from other colors unless the partner adds them
Vulnerable to board wipes and targeted removal that reset your investment
Pillow-fort, fog, and damage-prevention effects neutralize its combat plan
Guarantees a swing through for big commander-damage chunks when blockers stack up.
Lean into evasion and protection: add Lightning Greaves, Loxodon Warhammer, and a partner with built-in evasion or double strike to accelerate the kill. Pick a partner that expands your colors (Kediss for damage, or a multicolor partner for better removal and protection) and add tutors like Demonic Tutor plus recursion to rebuild after wipes. Trim do-nothing creatures for ramp and interaction so your buffed commander stays online.