Drifter is also used in the anime named "drifters"
On top of the manga called drifter (drawn by the same artist as Hellsing) which is an isekai where multiple historical figures ends up in a Fantasy world (for exemple Nobunaga works with dwarves to smith guns and with elves to produce black powder while there's a pro-human group/army ruled by Hitler which includes religious figures, the term was also used as back as in certain localization of the Inuyasha english dubs which defined a visitor who get thrown or fall or lost in the the demon world.
Well… this is interesting.
I wasn’t aware anyone else used the word “Drifter” to describe a reincarnated character.
I just started using the terms “Drifter” (someone that’s been reincarnated) and “Transient” (someone that’s been summoned/transported to a other world) as a way to categorize types of isekai characters with the vain hope that it would catch on as a trope.
I’ll take this as a minor success.