Yakou Madara's powers and abilities
Onmyoudo
A form of magic which is divided into two branches: Yin and Yang. However, this division shouldn't occur in the first place. As everything originates from harmony of Yin/Yang, they should never exist separately. However, none of this applies to Yakou's skills, since he uses his Taikyoku to use techniques, as a method that is unique only to him. Such techniques include: power words, sealing techniques, knocking people out with one word, creating mental worlds and pocket dimensions, creating dislocations in dimension for defense, redirecting lightning, flight, creating shikigami, and dropping a blazing comet on an opponent.
Tengan
The Heavenly Eye granted by Hajun, allowing Madara to observe the future's infinite possibilities across all of creation effortlessly, proving to be even more powerful than Ryuusui's Foresight. He can even use this while physically blind. Additional powers include: negating the attacks of Tenmas, using large spells with minimum chanting, and seeing into higher domains. The last of these also allows him to percieve the true names of the Tenma, weakening them
KokūzŠTenrei Gan, (虚空蔵天霊眼 ): An ability that allows him to have a higher level of perception and use large spells that usually takes hundreds of people a few days to complete with just a few words. It also allows him to disregard specific conditions of techniques and gives him complete control over the movement of stars.
Tengan―■■: After losing his original eyes, gained his "third eye". Manifesting in his forehead, they are more powerful than his original ones, capable of peeking into higher-order domains.
Tengan―Shinraden ,(天眼―森羅殿 ): The last vision gained by Yakou after his resurrection by Ryuusui. It allows him to see attribute of the souls of the deceased and give them the most appropriate afterlife and how the soul of the opponent will die. This eye showed him how to kill the shade of Mercurius and the path that the Eastern Expedition had to follow in order to kill Hajun.
Taikyoku
Taikyoku―Mukei
(ç„¡å½¢, Mukei)The result of his reaching the Throne while fighting the Tenma, Madara gains a "Colorless" Taikyoku. It allows him to do anything that falls under the physical phenomena of the universe and it is different from the ability to warp the laws of the world. Combined with his Tengan, it allows him to completely manipulate the movement of stars. However, due to his lack of desire, it doesn't grant him the special properties of Taikyoku, preventing him from warping existing laws and depriving him of the absolute defense common to other Taikyoku.
Keito Tentsui
(計都・天墜 ,Keito Tentsui) By creating a hole in the zenith of heaven with hand seals, Yakou causes the sky to be filled with a multi-layered mandala that shakes the elements of Heaven and causes a literal star to fall on his foes. This technique instantly kills anyone he targets upon completion without damaging the surrounding area.
Dimensional Fault
(次元æ–層, JigendansÅ), a defensive techinique, by creating dimensional barrier, Yakou can block most of offensive attack. In his second fight with Morei,he was able to block her law without her tapping into Taikyoku,by creating a 7 dimensional barrier. In the fight with Ootake, he deployed 24 dimensions layer of the barrier. It is said to be strong enough to halt even the attack from Kamunagara.
Yama Enraten
Madara's Transcendence-type Taikyoku that was born from the desire "I want to kill all", gained from confronting Ootake. Becoming a Sensory of Hajun, this allows Madara to realize the death of all creation. He can even kill his own concept of death, coming back from death received by Ootake's power. However, this Taikyoku belongs to Hajun, thus it can be taken from Madara by him.
Acta Est Fabula
Mercurius' Atziluth which allows him not only to control the time axis,the plot of everyone in his era and the beginning and endings,but also to erase the possibilities of someone from existence as it did against Hajun when the latter was weakened. Using his craving,he can emanate whenever he dies till he reaches the ending he wants and also created the concept of afterlife,granting to everyone its right place after death. Yakou troughout the story was described as being able to manipulate the concept of time,the movement of celestial bodies and during his battle with Ootake,the latter said that maybe the serpent was exactly like him while he was young. During the final battle at The Throne of Hajun,Habaki said that to match the shade of Mercurius,you need someone who have the same exact spells that the serpent have,which means that Yakou have all the abilities of Mercurius himself.
The first time he acquired this taikyoku,it was stated to be equal to Ootake several times troughout the fight,once Hajun blessed him,he killed the Tenma but died at the sight of the latter's nonexistent self. Once he was resurrected by Ryuusui,his power increased,matching that of the rest of the Eastern Expedition.
After his ressurection, Madara creates the concept of "post-mortem" and gains the ability to "judge after death". He can perceive the attributes of souls with his regained Tengan to grant the most suitable afterlife for each soul. In the Seventh Heaven's Era,He is as important as Amaterasu,the throne Goddess herself.