The chaos dragon does not respect FTB chunks claims, and completely bypasses them allowing servers to be completely griefed. It is one of the worst grief methods I have seen by far especially when using other mods to capture and teleport the dragon around. Please add some checks for FTB chunks, thanks.

EDIT: Another note maybe consider a way to respawn the dragon on islands for servers... :)

First, by griefing, you mean killing players, right? Not destroying blocks? Because it doesn't do that.

Second, there already is a respawn command. /respawn_draconic_guardian, if I'm not mistaken. Just /setblock on the original crystal's position to creat a new crystal, then summon a new guardian with the command.

If you ARE talking about killing players, then imagine if someone claimed the entire Chaos Island and completely bypassed the fight by becoming invincible to attacks from the guardian. That's a big fat nope.