Sacrifice room tile

I've read that there's only one sacrificial altar. If you used it already there's no altar that will appear anymore

There's a way to do the corruption chain at the end of your chain without sac chamber, but i dont have a link for it on my phone. You could look for it here on reddit, was under a post of something like "i looped my temple". If you dont find it, ill link it in like 6-7 hours