Assuming you have a DM who allows it, how would you explain a warforged character existing in the Forgotten Realms? The only non-hombrewed ways I could think to explain it involve travel via Spelljammer or somehow stumbling into Planescape's Sigil and then stumbling back out in the Forgotten Realms' Toril. If you have ideas, whether they would make sense with existing dnd lore or not, I'd be interested to hear them.
Assuming you have a DM who allows it, how would you explain a warforged character existing in the Forgotten Realms? The only non-hombrewed ways I could think to explain it involve travel via Spelljammer or somehow stumbling into Planescape's Sigil and then stumbling back out in the Forgotten Realms' Toril. If you have ideas, whether they would make sense with existing dnd lore or not, I'd be interested to hear them.
My gut instinct is to connect them to the lost magics of Myth Drannor.
Perhaps the character is the only one and was "awakened" after all this time?
Ask the DM. As the one in charge of the world, they're the ones who have to fit warforged in.
But, given the Forgotten Realms' have just about everything else, I wouldn't expect it's that hard to add them in.
I would say look up Lantan. Its closest in feel as far as technology goes.