Board Thread:General Discussion/@comment-4504826-20160516040951/@comment-25444898-20160808070015

No, Mettaton is the boss. The CORE is a part of Hotland, seeing as the kill counter for Hotland and CORE are shared. The Royal Guards are just "miniminibosses" like Lesser Dog or Doggo or even Shyren or Snowdrake. This is based off the fact that they don't have their own theme and instead use the "Enemy Approaching" song.