I notice that most people who watch this show or read the manga it is based on are unaware of a lot of things. I also see in so many disclaimers fanfiction that people do not give created to the author of the Journey to the West Wu Cheng'en as most of these characters are either Wu Cheng'en character who Minekura Kazuya used in her adaptation or religious figures. First is the fact that Genjyo Sanzo (Xuanzang Sanzang in Chinese) was a real person who lived in the seventh century CE and the Journey to the West novel is based on his Journey to India so how can Minekura own him? Nataku, Jiroushin, Li Touten, and the Jade Emperor are not Minekura original creations and are actual gods in Chinese Patheon. In her 'Comparative Analysis' Minekura said that Li Sei (Li Jing in Chinese) was renamed Li Touten also Li Sei was not evil in Chinese Mythology, but he was tempermental and he and Nataku did have a conflict, which each other, which was portaryed in the another Chinese Classic Novel Fengshen Bang. Also Nataku and Jiroushin Chinese names are Nezha and Erlang Shen respectively. Kanzeon is the bodhisattva of Compassion of Budhhism and not an original character of Minekura and he/she is dubbed the 'Goddess of Mercy' in the west, but bodhisattvas are not gods as gods supernatural beings or personifications who control a certain aspect of the universe or are in charge of overseeing human affair. A bodhisattvas job is to help enlightening those are experience suffering so that they individual may achieve Nirvana.
Also in the novel Mount Kaka (Mount Flower and Fruits) had 47,000 monkey and ape youkai, but most people seem to be unaware of this and assume that the celestial beings were not in the wrong for taking Goku from his home and from want I see in fanfiction people seem to treat the youkai and the wild life as separate entities when in fact the youkai both plant and animal are the wild life because most youkai used to be ordinary plants and animals or are descendants of those ordinary plants and animals, but through years of cultivate they gain sapient like intelligence and can have the ability to take on a human form. Also most people assume that Goku (Wukong in Chinese) was borned strong. Note that Goku in the Journey to the West novel was born the same way that this anime/manga was . His title Seiten Taisei (Great Sage Equal Heaven) is a reference that he has culitvated his conduct as he trained under an Immortal Patriarch by the name of Subodai (Subhuti in Sanskrit). Most people think that Goku being call the Monkey King has something to do with strength, but Goku was a literal Monkey King in the original story and had 47,000 subjects, and most people think that Goku could not have been a king in this anime/manga because he is a child, but Konseimaou the first anatagonist that Goku fights remarks that you are still in your twenties you do not even stand four feet from the ground not to mention Goku is not human so he may age different not to mention I have seen some boys in real life who became king at an early age. Another thing in the novel Gyumaou (Niumowang in Chinese and Bull Monster King in English) was Goku eldest sworn brother. Goku other sworn brothers are the Jiaolong King, the Peng King, the Lion Camel King, the Macaque King, and the Marmoset King, but sadly the other five sworn brothers almost never appear in any adaptations of the Journey to the West novel. Although some people like to make Gyumaou evil in some adaptation of the Journey to the West just because he is a monster in the original story he hardly does anything evil and thoughts does not show it either. He was just mad at Goku for what happened to Kougaiji (Hong hai'er in Chinese and Red Boy in English) as he told the divinities who confronted him to handed over his wife's Tessen Koushu/Rasetsunyo (Tieshan Gongzhu/Luochanu in Chinese and Lady Iron Fan/Rakshasi in the English) Palm Leaf Fan, and he said that you are not looking in the wrongs of this at all and that Goku stole his son, belittle his concubine Gyoukumen Koushu (Yumian Gongzhu in Chinese and Lady Jade Face in English), and defrauded his wife Tessen/Rasetsunyo by tricking her out of the fan. In other words he is show to be very caring towards all of his family members, but he is far from perfect as Gyoukumen asked Gyumaou to come and live with her because her father a 10,000 years old fox king died and she could not manage the property. Although Kougaiji is said to bad things like bully the mountain gods and local deities he was,but a child and yet he was not allowed to see his parents even after he was subdue by Kanzeon repented and also Kougaiji wanted to eat Sanzo flesh as Sanzo is the reincarnation of Konzen meaning that eating a piece of his flesh will grant one longevity and unlike this anime/manga this is not said to be a myth in the original novel. Also Gyumaou and Tessen/Rasetsunyo may have thought that if anyone was to punish Kougaiji it should be them and no one has the right to deny them from seeing their son. The Journey to the West 1996 televison suggest that this could have been how they felt in the novel, but this case is the primary reason why Gyumaou along with his wife Tessen/Rasetsunyo are villainized in some adaptations. Gyumaou is also villainized further for his marital conflict in the novel if you look at Tieshan Gongzhu (1966) and compare it to with Gyumaou characterization in the novel. Also antagonists and villains are two different things. Gyumaou and Tessen are indeed antagonist in the novel, but they are more stubborn and strong willed although Gyumaou is even more strong willed than villainous. The protagonist themselves did bad things in the novel as Hakkai and Gojyo murdered those innocent half human/half youkai children of the Yellow Robe Monster, but for some reason adapters of the Journey to the Westoverlook that.
Also note that Kougaiji is a fictional version of Sudhana who is the protagonist in the next to the last chapter of the Avatamsaka Sutra. So technically he is not even Wu Cheng'en creation, but Gyumaou, Tessen/Rasetsunyo, and Gyoukumen are. Tenpou and Kenren are the past live of Hakkai and Gojyo respectively as well in the original novel as well.
Edited 3 total times.