You read the title, i’m looking for a tag where the sub believes what they’re doing is perfectly normal.
I understand that it’s under other tags, but i’m looking to be more specific here.
Sorry if this has already been requested, i’m new here.

you've basically just described exactly what the altered_common_sense tag is for

Some other flavors of this concept include the tags "altered_perception", "unaware", and "exhibitionism".

All of those and "altered_common_sense" have definitions in the wiki here, if you'd like more details on what they entail on this site. The wiki is one of the big links at the top of the site.

I also don't know what you mean but you can try to add two plus or minus symbols after the tag on your search bar with another tag, (ex altered_common_sense++mass_hypnosis) and you would either get works with both tags or removes one you don't want

actually no you can't, and it's been like this for one or two years now, was steve rogers there when you were frozen in a hunk of ice

no? you just type in both tags for works with both tags, or tag and then -tag for works including one tag but excluding another