Derived from the weapon charms of the crossroads. As an action, you may attach a foci charm to a foci of your choice such as a druidic focus, holy symbol, bardic instrument, component pouch or arcane focus. You may detach a foci charm and reattach it to a new foci as part of the same action. A foci may benefit from only one weapon charm at a time. 

When buying this Foci Charm, select one damage type from: Fire, Cold, Lightning, Acid, or Thunder.

When casting a spell with this foci that deals the chosen damage type, add 1d8 to the damage result. This bonus damage applies once per spell slot.