Demons..basically ignore the existence of Damage Reflect.

I don't like Demon Avenger at all, but holy crap when he just powered through DR because he just healed way more than the DR I almost squealed in delight. That's not something you see everyday.

But I liked the Demon Slayer vids more, because I care more about DS. I understand that the Bishop's Holy Shell protected them from three of Arkarium's BS one hit kill attack, but there was one where I saw the attack hit him but he was still standing there. What was up with that?

The bishop had used Heaven's Door. Works like Soul Stone (buff in the top right corner), so when Ark's ohko attack hit the Demon Slayer they auto revived.