This is the second time I posted this, for the last link was changed.
First of all the Demon Slayer mod is in 1.16.5
It adds decorative blocks, weapons, armors and food!
You can become a Slayer by killing a demon / making a sun sword (Nichirin Sword).
Once the sun sword is made and held in your hand, it will get a random color (element) from 7/8 others.
To become a demon you need to find a special ore "Muzan Blood Ore".
To get demonic power packs you have to kill demons to get their power packs! 
