The Easy Way to Avoid Viper's Special Skill; Unlimited Invincibility Trick

Ever since I started playing Gunvolt, Viper has been the bane of my existence. He's simply the worst boss in the game, with an unpredictable attack pattern, lightning-fast movements, and--his most defining attribute--his catastrophic special skill, Sunshine Nova (aka Refulgence). 

This skill is incredibly hard to dodge normally. In the first phase of the attack, Viper throws a rain of small fireballs down on you, and the only apparent way to avoid them is to move slowly through the small gaps in the attack (and pray that you don't activate your command-dash). This strategy requires very pixel-perfect timing, however, and it's very difficult to get down.
I've always sought an easier way to get around this attack, as, to me, it just seems like the cheapest move in the entire game.
Welp, as of today, I've officially found an equally cheap move of my own to counter it.

Enter the "Chargeguard Pendant+", an item that creates an invincibility window for GV as long he's in his EP recharging animation. Simply double-tap the "down" button and you'll be invincible for about one second. Now, I had used this technique previously to dodge such attacks as Jota's special skill, but that was pretty much it. What I didn't know before, though, was that you can spam it for an unlimited invincibility window. I was initially under the impression that there were vulnerability frames in-between two charges which would render spamming impossible, but this is not necessarily the case. It was brought to my attention by a Twitch user named "Append" that, if you're very fast with double-tapping "down", a vulnerability window doesn't trigger. I tested this trick out for myself and, to my great surprise, it worked! I was able to stand right in the middle of Viper's Sunshine Nova, spamming Chargeguard Pendant+ invincibility, and didn't take a single hit! The one downside about it, though, was that I wasn't able to use my Flashfield during that time.
You can see one of my fights in the video below (apologies for the shakiness of the footage): 

As you might expect, this trick has many uses, not just helping to avoid Sunshine Nova. Try it out for yourself!
...Just don't let it ruin the game for you! Listen to Monica's advice!