I don't think there are any armors with Guard Up but Guard Up is inferior to Guard anyway.
But but but... I like blocking lasers =(
EDIT: Should probably actually ask a question here: seriously, how to not have [Gore Megala] murder the fuck out of you?
It sounds like you're a gunner? I'm a bit too lazy to go back and check your previous posts.
A lot of his moves are telegraphed, so learn to read those. For the bomb blasts you'll notice that they explode in a line perpendicular to where he's facing, so you can just dodge away from him and you shouldn't get hit. dodging to the sides will just get you hit by secondary blasts. Also be careful of this turn around swipe attack thing, if you aren't paying attention his tail will get you (it makes a loud whissh noise).
12. Eat fish and bread for defense up and that high chance of damage block.
Stewing has the chance of giving Weakener which has a chance that the monster doesn't have higher than average health and has some other effects (I think it can make the monster start out tired, and
there's a video where a Stygian Zinogre gets 1-shot but I wouldn't count on that happening to you). Point is it might make the fight go a bit easier. If you fry instead you might get Defender (Hi) which makes it so every once in a while the damage you take is reduced by a lot (you'll hear a little jingly and your character will sparkle). Either way you'll get Defense Up which should make you live longer.
You can always use mount bombing. Combine L bombs with scatterfish for L bomb+. Eating for combiner(hi) plus 4 combo books means you can bring 3 more L bomb+. Just remember to plant the small bomb a bit farther if your bombing him when he sleeps. That can pretty much end the fight as soon as he runs to sleep.
I'd suggest using paintballs or long reach weapon to activate bombs, myself.