"This is how you supposed to far crystals in Ultimate, pandemonium grands some nice value to them but mosters are the only way to actually farm pretty much of them in such time. Crystals are needed for different reasons, ESPECIALLY if you actually going for crafting these stupid 100 weapons cause last tower in infinity mode doesn't grand many crystals and you'll eventually run out of them.
I didn't cut anything in this video so you can see the entire way of farming these. It's pretty boring to watch so skip it to 37:11 or 39:40 (this one is better).
Here's the guide:
1. Pick up any of your promoted characters, you can also equip X weapon (if you have) with nice attributes as well for fast farming. 2 others better be as dynasty warriors type cause you can rush with their musou on horse.
2. Make sure that you have unlocked pandemonium difficulty permamentely (can be bought in upgrading camp).
3. Select Chapter 7 - Gaia, the Godness of Earth and do battle regular way until Himiko will summon monsters. Go into their spawn place (the one that closer to Himiko).
4. Keep defeating these, Himiko will keep respawning them but you get sometimes crystals for defeating monsters, don't worry about your allies as they'll keep up pretty well.
5. Once Hideyoshi defeated Himiko (that'll happen eventually) - continue a battle normal way and defeat remaining targets.
This way grands us from 40 to 60 crystals per 30-40 minutes, and that's faster than keep replaying any stage with 10 minutes being wasted and 10 crystals (overall) being received, so that's at least 2,5% of Weapon Master requirement with minimal wasted time.
The overall became possible thanks to 双葉 in this topic (i filled up the rest so you can farm it pretty easily in case if you struggle with crystals):
https://steamproxy.net/app/831560/discussions/0/1742268065069155071/?ctp=2"