I wasn't particularly pleased with the way that they showed our development as Zenos's One True Rival. There are two aspects to it that really get my goat.
First off, in our initial encounter, we don't even show as a blip on Zenos's radar. We. Do. Not. Impress. Him. At. All. There are others who've fought Zenos and failed to impress him, and they all have one thing in common: they are dead. Why did he spare us? There's no good reason for it, and there was nothing stopping him from dealing the killing blow. In my mind, THIS encounter is where we should have damaged Zenos's mask - NOT the second encounter. Zenos should have seen potential in us from the start, because otherwise leaving us alive makes no sense.
Secondly, the second encounter. It was just as much a curbstomp as the first. This was halfway to our final confrontation, and it did not appear as though we'd progressed AT ALL. Our attacks were just as ineffectual as in the first battle. While it's fine for it to be another unwinnable fight, it should have allowed us to seem like we're actually doing better than we were the first time. Like, cue Zenos's "I win" move at around 50% health, and allow our attacks to bring him that low in a reasonable amount of time.
FIGHT 1: *We barely scratch Zenos* Zenos: Bored now. Leaving. Also not killing you for no particular reason.
FIGHT 2: *We barely scratch Zenos* Zenos: You chipped my mask! Best Frenemies Forever!!!
FIGHT 3: *We curbstomp Zenos* Zenos: I knew you could do it! Now, I will turn into a snake, and we will fight again!
In the case of the Echo, it's known that the Echo affects different people in different ways. Not everyone with the Echo expresses it in the same way; for instance, Krile is able to use her Echo to trace aetheric signatures, something which no other Echo user has been shown capable of doing. It is possible that the Resonance also manifests differently in different individuals. It may be the case that Fordola got super battle intuition, and Zenos did not (he, instead, gained the ability to tame, control, and eventually to merge with Primals). So, we did not need a device to defeat Zenos, in spite of the fact that he, too, possesses the Resonance (a double helping, apparently). Of course, being Zenos, he likely doesn't NEED super battle intuition - against most opponents, at any rate.
Another villain laid low by ignoring rule 34 of the
Evil Overlord's List:
34. I will not turn into a snake. It never helps.