Forum:Quick question about Demise OTK

I was looking at the cards that should be in this type of deck and I have a question. Demise, King of Armageddon's effect says that he can only be ritual summoned by "End of the World". How is it that the ritual spell card "Advanced Ritual Art" would help in any way towards that deck. I understand that "Advance Ritual Art" is a very good ritual card, but if Demise, King of Armageddon's effect kind of contradicts the point of "Advanced Ritual Art" then how else would it become of any use. Can "Advanced Ritual Art" ritual summon Demise, King of Armageddon no matter what it's effect is? I'm confused towards this idea...