The Reincarnated Assassin Is a Swordmaster

Raon was once a loyal assassin for House Robert until Derus killed him. Not willing to give up, Raon prayed for vengeance and woke as a member of House Sieghart, the most powerful noble house. Though he carried over knowledge of a powerful Flame Link technique, he also carries the Curse of Bitter Frost, something that's slowly killing him. As if that weren't enough, the demonic embodiment of Wrath is trying to take over his body. He'll need all of their near-infinite resources to get revenge. (Source: MangaUpdates)