Someway I used a flask of winds that lasts 2 hours (with mixology) and then I used a flask of battle (the guild one) and then I don't know how it does increased the duration to 4 hours, yes I have the guild skill to increase the duration of flask of battle, but 1 hour + guild buff= 2 hours x2 (mixology) = 4hours.
If you use the normal flask, and then when its almost finishing you can use flask of battle and it will stack the guild bonus and mixology bonus (that does not stack when you use only the flask of battle).
Screenshot soon![]()