Beowulf was at lvl 11, I think. Vergil 2 is at the end of 13. When you fight Beowulf, you only wound him, taking out his other eye. He vows to hunt you down by your scent and leaves. Then, at the end of mission 12, a cutscene shows him confronting Vergil, who has the same smell, since he is a Son of Sparda as well. Then, when you get to Vergil, guess what he has? The Beowulf gauntlets and greaves. He fights you with them, and can Devil Trigger as well. He isn't easy. Haven't beaten him yet.
As for my weapons of choice...my equipment every time is Ebony and Ivory, Artemis, Agni and Rudra, and generally Nevan or Rebellion as a backup. Depends on what I hope to accomplish. If I am going for a brutal win, I use Rebellion. If I want to pump my stylish rating, I brutalize for a while with A&R, then switch to Nevan and pull off a killer Jam Session, which rockets Stylish rating through the roof. When I use this style, I generally keep an SSS rating. Oh, and btw, Nevan is good to have around because of Air Raid. You can only fly in Devil Trigger if you use Nevan, so generally I keep it as backup. Some missions you need to fly.