As with all Veilguard romances, improving your relationship with Emmrich has four main components. The first is just taking him with you on quests. Like with all of Veilguard's companions, Emmrich's bond and approval rating will increase once you complete a side quest or main story quest with him as one of your active companions.

The Veilguard has an excellent cast of characters, almost all of which are new to the series. However, it looks like there were once plans for a few characters from previous games to appear as party members.