She can tap some people and get an Allspeak wand. Someone asks who she is. Thor says "a visitor from a parallel universe."

She doesn't tell anyone otherwise. She thanks them for the wand and takes herself and Thor back to Wakanda. "Okay, who has a compelling reason to be able to operate in arbitrary linguistic environments and doesn't care that I have no way to verify that this one is like the kind I know how to use?" she asks, brandishing it.

"Sounds useful. Thor, you didn't tell us you had magic language powers!"

"I talk."

"You didn't just... think that people on his planet spoke English, did you?" asks Loki, bapping Tony on the head with the wand.

"Aren't you fifteen hundred years old? That's enough time to learn a lot of languages the long way."

"I guess, but it won't get you idiomatically fluent without practice with native speakers. There you go. I'd usually give you the user's manual but I don't have any on hand, ask me if you have a glitch, it sometimes has glitches, once I had all gendered words swapped coming and going for months in a language family before I noticed."

"You can ship that as a feature. Once the world's not ending I bet some people'd be all over it."

"Once things have settled down the user's manual will also tell you how to recreationally twiddle the vocabulary."

"How do I start speaking Latin, I want to start speaking Latin."

"It's a utility spell, not a recreational linguistics spell. You can write Latin if you attempt to write for an audience that reads Latin; speaking is just how you've always spoken but people'll hear what they need to hear."

"If I address a message to F.R.I.D.A.Y. and tell her to give it to Julius Caesar?"

"Might work, I haven't attempted the use case."

"F.R.I.D.A.Y., save this message until you've got a number for Caesar, the original, not the pizza place, and then tell him 'you may have been the emperor of Rome, but did you have a microwave?'"

Bystanders without Allspeak will hear Latin.

"Oh, that's nice, you could recover dead languages that way. If you know anyone who spoke them."

"That's all the historical figures I know, except Cap, and he speaks English."

"The Earth with the demons has a functioning afterlife, you can dig up whoever you like out of there even if nobody else has resurrected any of them yet."

"It sounds like they may not have Wakandans?"

"They might not have a Wakanda, you'd have to be pretty resolutely hidey to exist in some of these Earths without having made it onto the list of Earth countries, but it'll have emperors of Rome."

"The truth of Wakanda is very carefully hidden, but even before recent events it was known to the outside world that there is a Wakanda. They just presumed it poor, savage, and not worth stealing from."

"Yeah that's not the way to keep my folks out, they'd have turned up with an aid package and an invitation to join Vanda Nossëo."

"I think colonizers often arrive with aid and invitations."

"I will let you hash that out with Vanda Nossëo later, I am not the welcome wagon."

"Mmmhmm." She dismisses a hologram to empty some counter space for another one that's doing something more interesting.