You may cast this card from your graveyard, but not from anywhere else.
As long as Haakon is on the battlefield, you may cast Knight spells from your graveyard.
When Haakon dies, you lose 2 life.
Get Haakon onto the battlefield (he can only be cast from the graveyard, so mill or discard him first), then recast Knight creatures from your graveyard over and over. You grind value through a recursive Knight army, leveraging cards like Nameless Inversion and Reaper King synergies, and turn an unkillable board into either aristocrats value or wide tribal beatdown.
Insane resilience: Knights and Haakon himself come back from the graveyard repeatedly, making the deck nearly impossible to fully grind down
Mono-black gives access to the format's best tutors, ramp, and removal
Recursion of cheap Knights pairs beautifully with sacrifice and reanimation engines
Cards like Nameless Inversion become reusable removal/pump from the graveyard
Haakon must be discarded or milled before you can cast him, creating an awkward setup turn
Cost reducer and aristocrats payoff that drains opponents each time you recast a Knight.
Lean harder into self-mill and discard enablers (Stitcher's Supplier, Buried Alive, Faithless-style black discard) so Haakon hits the yard reliably turn one or two. Add fast mana (Dark Ritual, Jet Medallion, Bontu's Monument) and consistent tutors (Demonic Tutor, Vampiric Tutor) to find your payoffs, plus graveyard insurance against hate. To raise the ceiling, build toward a tight aristocrats loop using recurring cheap Knights plus drain effects for a deterministic kill.