Rosc |
It could be really fun. The only downside is the levels where you get dead infusions. After all, you're basically locked out of picking up form infusions, and not every starting blast has enough substance infusions to fill the gaps. I had the same problem when trying to build a Terran Firebat themed knight with Fire.
Phyisical blasts tend to have better luck, since fillers like Pushing Infusion are so ubiquitous among the elements.
If you start with Ice, then technically you can learn substance infusions that only work with Water Blast, if only because you're still in the same element. You can use them later on if you double down on your element and learn both Ice and Water.
Fun side note, if you're willing to play the long-con, Wood is a surprisingly good secondary element. Not only is Winter Blast really thematic to your idea, but with Expanded Defense you can dump burn to your normal/shield AC as well as your natural armor. Between that and the attack bonus from Elemental Overflow, you only ever need a belt of stats (I assume Str/Con) and the allmighty cloak of resistance to be competitive. That frees up a lot of gold for fun stuff.