You can craft guild alchemy in the Guardian of each city.
To craft a Guild Alchemy Stone you will need:
-

10x Fire Fragment ->

1x Fire Alchemy
-

10x Wind Fragment ->

1x Wind Alchemy
-

10x Ice Fragment ->

1x Ice Alchemy
-

10x Earth Fragment ->

1x Earth Alchemy
-

10x Lightning Fragment ->

1x LightningAlchemy
-

10x Darkness Fragment ->

1x Darkness Alchemy
You can add bonus to your Guild Alchemy Stones with

Reinforce Alchemy (The upgrade can fail)
Depending on the stone level you can add up to:
- Max 1 Bonus when the stone is +0
- Max 2 Bonus when the stone is +1
- Max 3 Bonus when the stone is +2
- Max 4 Bonus when the stone is +3
- Max 5 Bonus when the stone is +4
To add the fifth bonus to your Guild Alchemy Stones you will need a

Blessing Marble (Alchemy) (The upgrade can fail)
You can switch your Guild Alchemy Stones you will need a

Enchant Alchemy
No information at the moment