Yeah I don't hold the sidequests against Kato.
None at all? I can't really see that. Although I'm sure Kefka will be happy to hear of interps like that...
Even taking 50% of sidequests against Kato (what I do, for the record) makes him pretty unimpressive durability-wise. SH2 bosses go down like rag dolls in general (Arc Spells + four-person combo chains lead to insane damage, stuff like keys and Lucia's strike booster neither of which I personally used make this even worse) and while he's better than most (10k when the highest before him have like 6.5k) it's still not exactly impressive.
Catastrophe sure looks like it's omnielemental and it hits weakness on Zophar's magic-weak tentacle and there isn't much game to use it on aside from Zophar and the postgame. The fact that it's actually non-elemental seems pretty obscure to me.
We have a stat topic that can be checked for these things. Quite frankly I feel the opposite as you: "omni-elemental" is a largely fabricated mechanic (can't think of many games that use it) and certainly a more complicated one than the mechanically straightforward Lunar 2 seems likely to employ; the logical conclusion is that it is non-elemental. The game clearly has enemies which are magic-weak and not element-weak (also vice versa) which is illustrated very nicely in a certain earlygame dungeon, and Zophar's hand is one such (seemed immensely obvious to me given that it resisted physicals). And if you actually use Catastrophe in the aftergame, then you'll see quite a bit of evidence of it not hitting elemental weakness, of course. Anyway, why you would -assume- this strange mechanic of it I don't really know... but even if you do, to put it in a writeup without checking with the stat topic or people who know the game well seems kinda dishonest to me.
I shouldn't really heap too much blame on the writeup, though. Like I mentioned, I'm bitter, so take everything I say here with a grain of salt. It's just frustrating to see that falsehood aimed in a fight you feel strongly about and know there's limited things you can do in response because so many people will see it. It's even more frustrating when you do what you can (hey guys I have video proof!) and nobody responds or gives any indication of changing their vote, and I know for a fact some people didn't.