Sausage's legacy, the thing people will remember him for, is his service to Lady Death, and his deal with the Creaking Heart. The violence, the destruction, the hatred. This is what he'll be known for.
And in Red Kingdom they will remember it to be a tragedy. They'll know that it was out of care and desperation. That it was his intense loyalty to Red Kingdom, he want to save them, and his lack of time and options that caused him to fall into villainy. They will know him as a fool and an extremist, someone who dealt in things he didn't understand and paid the price.
Even Sausage, I think, wanted to be known for that moment. To be known as the person who ended the war by any means necessary. To be the person who would do anything, no matter how terrible, to secure their future.
But the truth is, that moment isn't actually worth anything at all, in the whole of Sausage's life. It meant nothing to the world. It changed nothing. The outcome would have been the same if he'd rejected the deal or not. He'd still have died that day. All of Blue and Red would have survived. The war would have continued. That moment isn't much of a legacy.
You wanna know what IS a legacy?
A mages guild, fully equipped with the materials to make any enchantment or potion. The knights barracks, there to train and house the Red's best fighters. The grand halls of the castle, with so much space that it'll take generations to use it all. And the walls and gates of the kingdom, strong enough to stand countless sieges.
Building all of that- that would be quite the impressive legacy.
So would be an alliance with Soluna, formed because the princess needed someone to train her, teach her magic in her kingdom's time of need.
Being a strong enough mage to be trusted with a task like that, by a king you've never met- that would be an impressive legacy.
Or just. Saving a life. Convincing someone that it's worth continuing to try. That their life is not yet hopeless. That the world is better off with them alive.
If you did that- then that person, their continued living, that would be your legacy.
Sausage did all of these things. But it's not what he's remembered for. Because he died the villain, he died in the wrong. He died because he wanted to protect it. He wanted his legacy to be saving his kingdom.
Nevermind that he already did. Nevermind that Red would not exist, without Sausage.
He was the necromancer, and all we know him for his what he destroyed. The damage he did. What he wanted to end.
Death is his only legacy.