Technically we didn't defeat van Hydrus, no, but close enough. In the first fight he withdraws because he has more important business to attend to. In the second, however, we are directly standing in the way of his goals, and van Hydrus presumably isn't holding back. He makes a tactical retreat that time because he recognizes that opposing us is folly (for the moment) and decides to live and fight another day.

All I can find from the Live Letter updates is that a confrontation with Garlemald over the Warring Triad is naturally inevitable, and seeing as van Hydrus is the CO of the VIth and stationed on Azys Lla right now, that we'd come to blows with him again is hardly surprising. I don't see anything about him being corrupted or descending into madness (though I won't be surprised if that turns out to be the case), and until such a thing happens or we get more hints toward it (or more info via a proper digest), I believe he could go the General Leo route as well. Seeing as 3.3's trial is Final Steps of Faith (vs. Nidhogg), Zurvan (Demon) and Sophia (Goddess) must be 3.4 / 3.5.

(As an aside, Kefka is only popular in the West thanks to his excellent localization. In the original Japanese VI he's just a psychotic moron and not too popular.)

We've done nothing but get humbled over 3.x. 2.55 had us get played for fools in the Syndicate's power games and ended with almost all the Scions ambiguously dead. 3.0 was mostly a long, sad track, learning that we'd been fighting for a false cause and being betrayed by the Archbishop, earning our victory at the cost of Haurchefant and Ysayle's lives and Estinien's autonomy. We, the players at least, also know that Y'shtola was blinded during our escape in 2.55 and is slowly dying as a result of using aethersense in place of eyesight. 3.1 had us learn that Thancred survived as well, only to have become magically crippled. 3.2 we learned Minfilia survived but has effectively lost her autonomy as well, having become a sock puppet Hydaelyn can use to communicate with us in the Astral Aetherial Sea.

... I guess that's not enough to destroy the Warrior of Light's self-esteem, though. They totally had it together in 3.2. /sarcasm

We're in dire need of some hope, not more trauma. Yet we know it's on the way, given Lord Edmont has already said that a new era for Ishgard will come at a heavy price...