Well I'd say you should look further into the other forum posts, this is a good primer to slayer: https://www.evernote.com/shard/s538/sh/b96ea117-4088-4ab3-a7bc-5c6e67f36ce3/b577c8d0e03bf36f6abdc30607300c2b
That's from the Memoirs of a beginner thread, looks alright
Here's Daymendou's 1.1 XRD Slayer guide that's more up to date: https://www.evernote.com/shard/s581/sh/1608847e-5259-49db-b877-6ced5c7e4e9b/b890a68e5246fc8e89f549984d7bd533
Other than that you should go through your Challenge mode trials to get familiar with the character's moves. Get used to using BDC, BDC FD/Mappa/Dandystep ect
Personally I think having proper movement in XRD and Slayer in general is key to taking advantage of him, so play around with FDC jump, all your air to air options, you'll end up getting a lot of air to air trades and converting on the fly off those, stuff like jP jP dj jSHD j2K jPD stuff like that.