I'm really glad you found the gameplay engaging and the juice satisfying! I was focused on invoking Judgement to feel as cool as possible. For "Q" and pulse weapon I'm realising that it would probably be necessary when waves progress and enemies fill up the arena and you need some kind of crowd control.
To get relics, simply keep purging enemies and you'll find your Revelation meter on the left filling up. Once its 100% you'll find a relic dropped in the arena. It's on me though because you don't really get any SFX that something dropped or that it even exists in the arena, I'll be fixing that post-jam.
Again, thank you for playing!