@Macavity12
ONLY read the first page of chapter 23 https://mangadex.org/chapter/813011/1 , DON'T SCROLL DOWN , you'll probably regret it.
'saito' means 'open' in this fantasy world's language: so morlock may have chanted something like 'open, door to another world, open'
but the spell may have interpreted it as 'saito, door opener (aka. locksmith) of another world' so saito was probably summoned by mistake
I feel dumb for not seeing this coming because this chapter happened just one chapter after saito was just isekaied in chapter 22 : https://mangadex.org/chapter/804006/4 and morlock reacting quickly was even noted by mevena the shop girl
@Hlz i mean, him being the spacetime wizard was already "hinted" at(or more preciesly spelled out) the book with the shroom, as much as it looked like a one of gag also was already present,
and with the fact that every extra so far was relevant in this part of the story, its not realy a deus ex machina, its somewhat sudden, but not a deux ex machina