Are you looking for an IC justification for Otto to be good with a sword, or are you looking for IC flavor you can use in your emotes? If it's the former, there are plenty of good suggestions. If it's the latter, I'll add to Merc's excellent suggestion an additional one: Look to fiction that has the feel you want. I've done classical fencing in the past, and tend to lean more towards unarmored swordplay on the rare occasions I RP it, so I take a lot of inspiration from Fritz Leiber's fiction - his description of swordplay in the Fafhrd and the Grey Mouser stories, for instance, is phenomenal. If you're looking for something more in line with heavily armored military swordsmanship, you might look to George RR Martin.
Find fiction that describes the style of swordplay you want to use (extra points if it's described in a way that you want to emulate!) and steal from it! We're all thieves in roleplay!
Find fiction that describes the style of swordplay you want to use (extra points if it's described in a way that you want to emulate!) and steal from it! We're all thieves in roleplay!
