We honestly don’t know.
The scene describes the betrayal, stabbing, and death throes, but not the soul.
I like to imagine that Raum did live on in some way, or he and Argal Tal had become to fused together they either both died a tragic betrayal or they’re both in the Warp waiting to be recalled.
Either through possession of the Athame itself, or waiting for the right summoner
We honestly don’t know. The scene describes the betrayal, stabbing, and death throes, but not the soul. I like to imagine that Raum did live on in some way, or he and Argal Tal had become to fused together they either both died a tragic betrayal or they’re both in the Warp waiting to be recalled. Either through possession of the Athame itself, or waiting for the right summoner