LeeRoy; The mecha didn't open it's mouth, it simply fired the beam without warning. That's why it's teeth got blasted apart, it skipped the "Let's open it up and prepare to fire"-phase. I like your escape though, much fun ^_^

Beta; It's cool that you're using techniques and all, but does it really function as a dodge-no-matter-what thing? Also, you're been charging your armor up until the last post, correct? So if you're planning on using that other super destructive spell of yours, that's gonna take you another three posts, no? 

Regardless, you should describe the actual dodge a lot more. Right now you're just saying that "I use my dodge technique to dodge. Now I'm on his foot."

Oh, and the beam is also triple-charged, so there's that.