Yaksha (Sanskrit: यक्ष, yakṣa, ञक्ख, yakkha in Pāli) is the name of a broad class of nature-spirits, usually benevolent, who are caretakers of the natural treasures hidden in the earth and tree roots. They appear in Hindu, Jain and Buddhist mythology as a kind of nature spirit, whose female counterparts are Yaksini. In Hindu, Jain, and Buddhist mythology, the yakṣa has a dual personality. On the one hand, a yakṣa may be an inoffensive nature-fairy, associated with woods and mountains; but there is a much darker version of the yakṣa, which is a kind of cannibalistic ogre, ghost or demon that haunts the wilderness and waylays and devours travelers, similar to the rakṣasas. They also follow Bishamonten, one of the Four Heavenly Kings.
Yaksa appears as an optional boss, who can only be fought if Tamaki Uchida defeated the Oni in the World of Pride. He will attack the party to recover the item the player gets in the room guarded by the Oni, which can be a sword named "Karyuma" or a Spear named "Kyouki".
Shin Megami Tensei IMAGINE
Yaksa can only be obtained through fusion. He appears as a mini-boss on B9 of Old Ichigaya Camp's gold instance and by using the HDD he drops, players can summon Bishamonten and his Yaksa minions into the boss room alongside [[Jikokuten].
Devil Summoner: Soul Hackers
"A spirit of demigod status that serves the Hindu god of wealth. It lives in the Himalayas and guards treasure. It is a holy spirit of sorts that lives in other worlds, in the air, in forests, and underwater. It is known as Yasha in Buddhism, and protects its teachings. It prevents invasion of homes by evil spirits, grants blessings to the good, and devours the evil. It is a benevolent god in India, but in Japan, it is known as a dreadful man-eating demon."
—Devil Summoner: Soul Hackers 3DS Compendium
Yaksa can be first seen in the Algon Main Building. In the 3DS remake, a variant Yaksa can be purchased from Nemechi (dango form), and costs 300 D-Souls. His artwork is based on his design from Shin Megami Tensei: Devil Summoner. This version is more adept at spellcasting.
Digital Devil Saga: Avatar Tuner 2
Although not actually the demon appears in the game, "Yaksa" (jp: 夜叉鬼, Yashaki) is used to categorize demons first "tuned" in the "real world" during boss battles. The usage is never explicitly explained in the game, but it is probably for distinguishing the demons of Asura class, which takes form initially from the virtual world, Junkyard, of the "Asura Project" such as Varna and Agni. In this sense, Varnani and Indra belong to the Yaksa class. It also explains why Vritra, which is transformed from a Junkyard AI, is titled Yaksa instead of Asura.
Devil Survivor 2
"A spirit of demigod status that serves the Hindu god of wealth. It lives in the Himalayas and guards treasure. It is a holy spirit of sorts that lives in other worlds, in the air, in forests, and underwater. It is known as Yasha in Buddhism, and protects its teachings. It prevents invasion of homes by evil spirits, grants blessings to the good, and devours the evil. It is a benevolent god in India, but in Japan, it is known as a dreadful man-eating demon that kills men and devours their bodies and souls."
