A black metal/folk metal band from Taiwan, they have been around since 1995, and have made 5 studio albums, and are scheduling their newest album for june of 2011. Their lyrics focus mainly on the subjects of Chinese mythology, Taoism, and political stuff.
Their band name is pronounced Thonic, not Kthonic, Chuhthonic, or anything else.
Metalhead1: "hey, have you heard of that black metal band from china? I forgot their name, but they're pretty good"
Metalhead2:"yea, dude you must be talking about Chthonic! you have good taste :P"
Aside from its conventional meaning (look it up) can be used as a substitute for 'cool' or 'worthy' in the company of fringe metalheads and acolytes of the Necrowizard.
Amon Amarth are chthonic as fuck.