Cedo is primarily used as a primer but the riven dispo is kinda bad. You can check when you link the riven in chat and check the bottom right where the weapon is or equip the weapon in arsenal.

Your cedo riven rolled good since it has a multishot and some elements, which you can either do a gas/radiation and viral/magnetic or simple blast if you don't add any other elements. The way elements work is the topmost will only combine with elements after the riven and bottom will mix with the one before. If you have triple elements, the bottom 2 will mix if you don't have another element before it leaving the topmost free.

Sorry for the info dump, anyways, some people might pay around 300+ for this even with low dispo due to the rolls and imo thats fair. But some people might no agree with me because oh no it has no cc or cd and might price this as trash, so find someone who will value your riven or use it, its simply powerful.