Sirac of Suzail

 is an NPC who has been added to the Winter Festival in its 2016 edition. He will trade certain special "fish" from that event against selected campaign currency.

Location
Sirac of Suzail will give you old campaign currencies for those. He is to the right and up some stairs from the mayor in the center of the winter festival area

Tyranny of Dragons Campaign

 * 10× = 1x
 * 5× = 1x
 * 2× = 1x
 * 2× = 1x

Sharandar Campaign

 * 5× = 1x
 * 5× = 1x
 * 5× = 1x

Icewind Dale Campaign

 * 5× = 1x
 * 5× = 1x

Dread Ring Campaign

 * 6× = 1x
 * 4× = 1x
 * 2× = 1x

Sirac von Suzail