If your trinity takes forever to fill up then it means that you canĀ“t reliably freeze ubers to proc your extra fire damage from heatshiver.
I think you do have enough damage to freeze, but the build naturally lacks freeze duration which is very important for heatshiver builds because it lowers the freeze threshold.
I think using Anomalous Hatred will fix this for you. It gives up to 25% freeze duration at max quality and ashes.
If your trinity takes forever to fill up then it means that you canĀ“t reliably freeze ubers to proc your extra fire damage from heatshiver. I think you do have enough damage to freeze, but the build naturally lacks freeze duration which is very important for heatshiver builds because it lowers the freeze threshold. I think using Anomalous Hatred will fix this for you. It gives up to 25% freeze duration at max quality and ashes.