9(TTIRAAS)

An Au where Rimuru isn't the only one to be reincarnated in Tensura and have his new body born from a True Dragon's magicules.

Tamura and his fiancé(who I forgot the name of) also end up dying because the robber or whatever had a gun instead of a knife.

Rimuru is still named such and his new body born from Veldora's magicules like in canon, Tamura was born from Velgrynd's magicules and his fiancé was born from a mixture of Velzard and Guy's magicules(if they were also born in slime bodies is up to the writer).

The three somehow can mentally communicate with each other so they try to meet each other again but it is hard for Tamura and his fiancé taking in account that Velgrynd and Velzard took them as their children and wouldn't simply let them go.

So the three were living separate lives and training to be strong but also communicating so Tamura and his fiancé gave ideas for Tempest and what Rimuru could name his people, etc.

Maybe they could finally be able to meet at the festival in Tempest? Tamura could have been sent with Bernie and the other girl to keep an eye on Masayuki and spy on Tempest while his fiance could have asked Guy's help to convince Velzard to let her go to the festival?

Anyway, anything else is up to the writer like Tamura and his fiancé's new name, how them ending up in Tensura changes the story, how they are 'raised' being their dragon mother, ships, etc