Yeah this episode is going to primarily be remembered for the Maiden fight, no question. A lot of stuff that seems inspired from other series seems somewhat out of place with RWBY, but considering we've never seen a proper fight with people in this world that have abilities that go so far outside of the established norm it comes out alright. Also it sets the standard for future fights involving Maidens and non-Maidens with equivalent power, as well as Salem or Ozpin eventually.
As for the rest of the episode, Jaune's semblance isn't healing per se; more like expending his own Aura to supercharge someone else. As Aura is what heals wounds this simulates that effect, but also appears to have battle implications. At least that's what I'm getting with Weiss pulling out the Queen Lancer as a summon, but more on that in a bit.
So Hazel's semblance is IGNORE PAIN! Goddamn, I was really looking forward to Hazel being an intriguing character in terms of depth, but he's got the most boring motivation and semblance I could have come up with. He's essentially Bane, that's it. Massive letdown. Doesn't mean he's not fun to see charge around like a Berserker, but that kind of character slot is better suited for a fodder mook so I'm not convinced that Hazel will be a relevant threat from Salem's organization for too long in the future. Seeing Nora get the electric charge from him was as fun as was expected, and sending him flying outside where we transitioned to Adam and the White Fang was a nice touch.
Than we get to Blake appearing to try and get Adam and his followers to stand down. To be honest... it started great, with the speech, the many other Faunus from Menagerie appearing alongside Blake, Sun, Bagherra, the Mistral Police arriving in an airship as well to arrest them. Even Adam's response to try and detonate the bombs to kill everyone there, followed up by him lashing out in desperation to slice Blake and than get smacked down for it.
...And that's when the scene became a massive disappointment for me. Despite Adam's followers clearly shocked and confused that their leader was about to blow them all up about 10 seconds ago, they immediately follow his orders to 'kill everyone there' when they are vastly outnumbered and outgunned. Followed up with only our important characters in the scene (Bagherra, Sun, Blake and Illya) taking care of most of the 9 other Fang members, and it completely took the piss out of the whole need for the Faunus militia. Sure they'll still be needed for Volume 6 and potentially beyond when the rest of the Fang learn what happened at Haven Academy and that their leader has been arrested, but it felt like they were just there to be shown and nothing else. Feel like it could have gone two other ways; the Fang members stand down because they know they have no way out, or don't want to fight friends and family as at least ONE of them noticed, or have the Faunus militia actually be the ones to charge in and take them out.
Hazel meanwhile gets impaled and dragged back into the school building by the previously mentioned Queen Lancer stinger from Weiss, and we finally get all 4 members of Team RWBY back in one place for a few brief moments. Yang than makes her break for the Vault elevator in the confusion, slipping past Emerald and detaching her arm to get past Mercury with Weiss as backup. The Blake/Ruby headnods will probably annoy some people, but the message to each other was clear to me: 'Go do what you have to do, we'll catch up after this is over.'
Back to the Vault, I'll bypass the Maiden battle since I described enough of it up above and it really needs to be seen to evaluate your own opinion of it. The end was neat to see that Vernal wasn't dead but was at the door (both Death's and the Vault's ironically) and was able to get a shot off on Cinder from behind, giving Raven an opening to slam her with a Maiden-empowered fist (I apologize but I honestly can't think of a better way to describe it at the moment) that sends her flying off the side of the vault and down into the abyss, with Raven freezing her solid as payback for what happened at the end of the previous episode.
That whole ending was nice and poetic, but the pacing was off with how that kicked off. The delay from when Raven told Cinder to 'watch her back' and Vernal finally firing the shot was agonizing and far too long for the impact that was supposed to have. Still, animation delays have always been a staple with RWBY, and until they fix that on a regular basis the action sequences will never be that amazing.
Raven than says a few words for Vernal after she finally expires and closes her eyes, and than opens the Vault door revealing a truly unexpected scene: A desert world that may or may not be Vacuo with what appears to be a chalice of water on an altar. (I personally don't believe it is Vacuo, otherwise someone could have eventually come across this suspicious looking vessel on a pedestal in the middle of the desert) No clear shot of what the relic actually is, but considering we know it is the relic of Creation, something water-related isn't too hard to speculate. Also my mind immediately flashed to the Mortal Kombat movie and the terrible line of 'USE THE ELEMENT WHICH BRINGS LIFE!' so you know... that's a thing. But before she can step through, Yang arrives to confront her mother and the episode ends on that. *Edit, it's the Relic of Knowledge so everything I just stated there is moot.*
So, what to process from all of this? The fight in the schoolroom seems reset to Ruby, Weiss, Ren, Nora, Jaune, Qrow and Ozpin/Ozcar vs Emerald, Mercury, Hazel and Lionheart. Big numbers advantage there, so it feels obvious which way that should go, especially given the other things I'm about to list. The White Fang is down, captured and arrested by the Faunus from Menagerie and the Mistral Police, Cinder has Fallen, (Come on, I had to get in one pun from that obvious bait) the Relic of Knowledge has been revealed and unlocked, and Mother and Daughter are about to confront each other for it.
Given that so many things went the good guys' way, (or to be more correct, against all of the antagonists) I'd say that the other shoe is likely to drop in the Vol. 5 finale, and HARD. We never actually saw Cinder 'die' so I'm certain she'll come roaring back and potentially kill Raven, with the Maiden power moving to Yang and everyone will squee like crazy. Adam is likely going to find some way out of his predicament or at least kill someone important in the cast before he's finally subdued, and something bad still has to happen in the main room of the school since Qrow and his bad luck is still there. Or maybe the last episode will be all sunshine and rainbows, who knows. Personally, I think we're in for a roller coaster.