With a little bit of ramp and plenty of inkable cards, youll be taking control of the game
Mordenkainen Six mana is a lot for a planeswalker
While you do lose access to a lot of the strong mono-white and Orzhov lifegain cards, black supplies enough draining cards to support the theme relatively well
#2 Demonic Tutor Demonic Tutor Commander Masters, Mythic Maybe I overvalue tutors in competitive Commander, but I think they are great
Being a creature means that it has some vulnerabilities that Cori-Steel Cutter doesnt have (Cutter doesnt die to Doom Blade) but the token making mode creating 2 bodies makes it if you get it to Raise the Alarm once, its fine if it gets Doom Bladed, and if it you get it to trigger twice, its on the better side of cubable 3-drops (even with the high competition there.) There was a minor theme in Kaldheim with the cast 2 cards with cards like Clarion Spirit, Codespell Clericand Bloodsky Berserker had such bad floors that only Clarion Spirit got played in cubes, and even then, not that often
There are enough black Commanders that make incidental tokens or play in aristocrats that this card is actively going to be quite good