My playthroughs got derailed a bit by Football Manager this week, so I'm still not done with Death Howl. Will hopefully be finishing it up over this weekend, depending on how much more content there is. Not any real further notes from last week, and I'm still overall enjoying the game. The battles that are at the core of it are fun, and I am enjoying the deckbuilding even though it's more puzzle-like than open ended. Each region has two play style archetypes and a certain set of enemies and encounters, and for each fight/zone it's more a case of "what does the game want me to do here" rather than "what can I do with the cards I have".
As for Elden Ring co-op, I'll leave that to those who are more enthusiastic about the game than I am I think. I had my fun with it and got my money's worth but I am not that interested in going back for seconds. Also social anxiety and all that, I'm not sure I'd be that comfortable anyway, or that good company for that matter.