To be quite honest, I had my Blitzfrost for ages before I finally read the fine print. In fact, I complained about it's icy grip being fairly useless. I'd lock an enemy in place and still get destroyed because, well, they can and do return fire. Then I noticed this tidbit.

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Using this ability has saved my backside many, many times from certain obliteration. 

Now, I use icy grip before starting an attack outside it's lockdown range.

Is it foolproof? Nope. But taking 50% less damage from return fire certainly improves your odds.

As a side-effect I'm rapidly closing in on completing  the Blitzfrost's individual task with cryo launchers.

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Hope this helps, and happy hunting!