Backstory help - Aasimar origins

[Kaibis]

We are about a dozen sessions in and the characters are getting to know each other more, my backstory needs some fleshing out, but I don't know the FR lore well enough.

My backstory so far:

The Paladin was high ranking in an order of knights for the God of Torm (or Helm). I liked the idea of them not being from the material plane, only arriving here recently, maybe within the last ten years.

Is this possible?

[Honest Tiefling]

You'll need to run this by the DM. Having a character from a different plane of existence can change the tone of the game, and your DM might not be up on their celestial lore. But yes, it is highly possible, depending on the edition. (planar stuff gets weird, FR has a lot of older edition weirdness and retcons in this department).

There's no harm in asking, but I do predict that this request won't have the best success rate. Might I ask what is appealing to you about the idea, and how you envision it working with the roleplay of the other characters?