What exactly was Roswaal's role within Re:Zero? I have just finished the anime, and althugh given that the show did a really good job at tying up loose ends with the plot, I still do not get Roswaal L Mathers' purpose within the plot. According to my memory, he was/did the following:


   - Head of the mansion and the Mathers Domain
 - Helped with the fight between Subaru et al. and the majuu packs
 - Sponsored Emilia for the election

 ...But then he wasn't seen within the show afterwards (for the latter section, at least).


Did his character play a bigger role that I overlooked? (Or potentially in a later release of the manga that has not been anime-tized?)
Roswaal has ulterior motive. It is not shown in anime adaptation. Yet, anime covers only three first arks of the light novel. His motive is fully explained in ark 4.


   His goal is to meet Echidna, Witch of Greed. This is why he helps both Emilia and Subaru.