A Combat Mana Flask is an item that cannot be put into your vault or traded. It restores 100% of your MP (Mana Points). In addition it can only be used in certain places (Goldenia Rainforest, Dragonspine Battlegrounds, and Sengolia Battlegrounds) You can get them by exchanging 10 Bronze Honor Badges for 10 pieces. You can buy them in item shop for 25 crystals and you can also win them from Dragon Hunt.