I'm surprised I held top XP for so long, and also that I'm still holding top time by a whopping 5 minute margin. I guess this was just one of those days.
As for the Wicked Guitar, it's especially well-suited to this scenario. The Dragonspawn are really the only reliable form of blood cow; the Shades and Bandits all have interactions with the curse world transition and can't be "harvested" reliably, while Animated Armors can only be used as blood cows under rare circumstances and Thralls are of course bloodless. This means getting the Dragonspawn that are available to the right level is really beneficial. The additional difficulty isn't actually bad either. You're immune to the secondary effects of Thralls so beating through them isn't too hard if you have blood cows, Shades are nastiest for their secondary effect which has already been triggered anyways if they're tagged by the Wicked Guitar, and Animated Armors don't gain an additional layer of DP so they don't take much more resources to take down. Altogether, this is probably one of the more ideal situations for the Wicked Guitar.