Avengers 4, probably:

arcano-cosplay:

Tony Stark: So, we’ve got this, we’ll travel in time, bring back the dead Avengers and…

Thor: And Loki.

Avengers: ^tense silence

Clint: Thor, you know, maybe…

Thor, in full thunder mode, throwing lightning from his eyes: AND BRING BACK LOKI!

Tony Stark: Sure thing, buddy!