Quote Originally Posted by Unregistered View Post
Which SP quest drops holy crystal of light?
They're more common at the Standard+ difficulties. You can also combine/upgrade jewels into crystals via the Material Exchange in the Shop.

The only upgrade materials you can't obtain this way are the Idea Cores from Raid Bosses, the Fangs from SP quests, and the books from (mostly) events.

Quote Originally Posted by Unregister View Post
Is it better to run 25 stamina sp or 8 stamina for gorgon fangs?
If you can handle it, the 25 Stamina/Expert will net you a LOT more/valuable upgrade materials in general. That said, Expert isn't easy to farm into until your Kamihime are around level 50; even then it could be a little rough depending on your comp. Even if you're only after the Fangs, I'd still probably suggest running atleast Standard difficulty because Beginner drops are kind of abysmal in general.

Personally speaking, I never got Fangs to drop from the non-expert SPs on the DMM version, but the JP wiki does list them on the drop table. I think it probably took me around 12-15 expert clears to get my first fire fang to drop. (I got 2 water fangs within 5 runs though, so it's really luck dependent.)