I want to know important thinks
is better staff or rod with it?
will be a nice combo cryo with elementalist?
Well, I’m playing Cryomancer right now. Even though you haven an attribute that boosts your ice skill, if you’ll become an Elementalist, I’d use staff, since you won’t be using only ice skills. 
If the weapons available to you doesn’t give a specific bonus like " All cryomancer skills +1 ", then go for the one with higher Magic Attack.
afaik there’s an attribute you can get that makes frozen enemies take more damage from lightning attacks so yeah you can do a good combo.
Cryomancer have an attribute that increases 10% x (Attribute level) damage from lightning spells when the target have the Freeze status, and element have an attribute that increases 50% x (Attribute level) damage from Electrocute when the target have the Freeze status.
Yeah for that i think cryomancer with a ele will be a strong combo, but aobut the rod the cryomance have a an atribbute with rod.
Is cryomancer better than pyro??
If the attribute is like Pyromancer’s one for Fire, its max level is 3 or 5, I can’t remember. But anyways, the damage it gives is really low, so don’t chose your weapon based on that.
The weapon he’s talking about increases all cryomancer’s skills level by 1. It’s a level 40 weapon and also has a high magic attack value so it’s really useful