TL;DR im playing a version of Sanguinius i built for a DND5e short campaign, DM allowed me to homebrew his weapons. Starting at 11. How do i homebrew these things so that they fit in Faerun?

So we're doing a mini-campaign, and ive decided to play a Faerun version of Sanguinius from Warhammer 40K. I built a protector Aasimar folk hero, fighter champion with the lucky feat. Were starting at level 11.

The DM has allowed me to homebrew his weapons, and im struggling to come up with something reasonable based on his stats.

What ive got so far, as a base:

Spear of Telesto - halberd, either 2 or 3. A ranged attack that deals 4d6 fire damage to enemies in a 30ft line.

Moonsilver - a silver longsword

Blade Encarmine - a greatsword of warning.

My goal wasnt to get him as lore accurate as possible, but represent a different Sanguinius if he had had a relatively decent childhood on Faerun, with nods towards his 40k counterpart.

Any input would be helpful, thank you!