In Ep. 24, Hao basically annihilated Team X-III of the X-Laws. Outside of the inconsistent quality of the drawings, the overall execution was pretty solid. The episode had its good share of tense and heartwarming moments, and it leveraged the anime's soundtrack rather effectively.
The question is, if you watched or read my review of Ep. 24, how did Hao survive after Chris depleted all the oxygen in the arena when the Spirit of Fire uses oxygen as the intermediary?
The episode adapts Chapters 140-143 of the manga. The first half mostly covers how Hao survived the hypoxia environment while the second half covers the backstory to how Hao's present incarnation came to be.
As the smoke from the grenade explosion finally dissipates, everyone notices that Hao's Spirit of Fire changed color and element. Once red, the Spirit of Fire is now blue with water flowing down from its body. Everyone is baffled at how Hao can just change elements at will until Yoh's father, Mikihisa, explains the Onmyōdō. Having mastered the five elements (fire, earth, water, wood, and metal) during his first life, Hao is able to temporarily transform his Spirit of Fire into the Spirit of Water, thus also changing the intermediary. As the X-Laws mourn the losses of their comrades and Yoh's friends confronting him on his connection with Hao, Hao has the Spirit of Fire consume the spirits of Chris, Cebin, and Meene to further boost its already gargantuan power.
Hao's Onmyōdō changes the affinity of his Spirit of Fire to water.
The Spirit of Fire about to consume Chris, Ceben, and Meene's spirits.
After the match, Silva asks his friend Radim to give him the recordings of Hao's techniques, but the latter warns him of the perilous situation he will get himself into. Regardless, Silva snatches the camcorder and leaves with the footage. Meanwhile, Yoh and his friends are off fishing at the ocean where the former finally opens up about his relationship with Hao. The anime cuts to Yoh's grandparents on their way to the shaman tournament as they recall Hao and Yoh's birth.
Silva snatches the camcorder from Radim.
The second half of the episode is mostly a rehash of the beginning of Ep. 1 with some additional storybeats. Yoh's mother was pregnant and Yohmei, Yoh's grandfather, learned through his divination that Hao would reincarnate back into the Asakura bloodline. However, as his mother was bearing twins, the family was not sure which one would be Hao. As a result, the family made the hard decision to kill both infants. Unfortunately, as soon as Hao was born, he already could summon the Spirit of Fire and easily repelled Yohmei and Mikihisa's attacks before disappearing. The day after, the Asakura family lamented how Yoh's fate would be long and arduous before the episode concludes.
Yohmei summoning his shikigami to kill the just-born Hao.
A small Spirit of Fire holding Hao.
This was a pretty slow, but still well-paced episode. The first half was a very nice info dump on the lore behind the 5 elements of the pentagram and Hao's Onmyōdō. Later in the first half, the episode does a really good job progressing the character dynamic between Yoh and others. Earlier in the series, the anime would drop hints of Yoh's reluctance to fully divulge on his and Hao's relationship. Seeing Yoh finally opening up and his friends still accepting him plus willing to bear his burden were heartwarming.
Art-wise, I was glad to see this episode returning to the usual consistency. The artists did a rather good job diversifying the color palettes from scene to scene. The shot of the Spirit of Fire about to consume the spirits of the deceased Team X-III effectively captured the terror with the reds and blacks, and the glowing yellow eyes. The scene where Yoh was fishing at the ocean before he finally opened up about his and Hao's relationship used a more subdued, grayish color scheme for a more melancholic feeling.
Unfortunately, what sort of dragged this episode down was the second half and it's to no fault of the episode itself, but rather the weird decision to show much of the same scene in Ep. 1. In one hand, I can sort of understand why the studio showed Hao's birth in the first episode to establish the antagonist. However, doing so led to redundancy. Personally, I would have kept that scene under wraps until this episode for that surprise factor. To give the episode some credit, it did provide additional scenes, particularly the conversations between Yoh's mother and father prior to Hao's birth, and they did a good job establishing their characters. On top of that, the soundtrack during the second half really hit it out of the park, especially the acoustic piano version of the main theme.
It's hard to really judge this episode due to the weird decision to spoil Hao and Yoh's relationship in the first episode. As a standalone episode, I would say it is really solid.