So I have been looking around and it looks like I get different items from red crystals depending on what demon type I have. The only problem is I couldn't what is the best demon type to use. Can someone please help me. --- Xbox Live Gamertag: Bruceky
Use the Undead or Show-Off type demons to open them, since they get those Valuables items that you sell to Konnou-Ya for cash (Wood Ornament, Asuka Mirror, Rakuyou Chalice, etc). Wood Ornaments sell for 1000 Yen and you can even get something like Roman Coins that sell for 13,000 sometimes, well worth it). Sometimes, Seductive and Jack types can get Incense items, but I don't deem those worth it since it's not guaranteed. You're at least guaranteed to get a Wood Ornament. But the possibility of getting something more valuable is worth it. Plus, I guess you could just save and reload if you're really particular about it. Never bothered doing so and I still ended up with a ton of cash in the end. Beast and Old Man seem to get Sake items, which are good sources of cash though, but still not as much as some of those Valuables. You should be using a demon with the Scavenger skill at all times so you can get some rare items every once in a while anyway.
Undead demons are Turdak, Hitokotonusi, Arahabaki, Ippon-Datara, Oboroguruma, Legion, Ichimokuren, Rakshasa and Ghoul.
Show-Off demons are Obariyon, Mokoi and Thoth.
Skill Thoth was in my arsenal the moment I got him since he drains every element and mind attack. He is weak to death and physical, but I gave him physical resist to cover his weakness and cut physical damage in half. Very useful for any battle that doesn't deal with Death skills. He doesn't have an active attacking skill though, only downfall. So I used him to open every red crystal I encountered since he'd be tough enough to survive mostly any battle by himself if needed.