A group of scientists uncovered a mystery monolith near Lake Turkana in Kenya in the twenty-first century. The substance within it, later known as the Zohar, soon became a source of enormous power. Humanity finally reached the stars, establishing the Galaxy Federation and conquering known space.
Humanity has long left the planet Earth, which has been renamed Lost Jerusalem and obliterated from star maps, in the year 4767 T.C. (Transcend Christ) or 7277 A.D., according to the ancient year-counting system. The original Zohar substance was found to be too toxic, and it was sealed on Old Miltia, forcing most humans to rely on less powerful Zohar emulators. Some organizations, however, still yearn to rediscover the true Zohar, believing it to be the path to Lost Jerusalem.
Meanwhile, a new alien race known as Gnosis has appeared. The Vector Corporation creates KOS-MOS, an android, as the ultimate weapon against the Gnosis. Shion Uzuki, the project’s leader, is a young engineer. The Gnosis attacks Shion and her team after completing KOS-MOS. Shion becomes the target of the terrorist U-TIC group and other mystery characters due to a series of events, the purpose of which appears to be the secret passage to Old Miltia. Other characters become involved in the conflict. Shion eventually realizes that she is not alone in her struggle and that the initial Gnosis attack was only a tiny part of a larger conspiracy.
The first episode of a trilogy, Xenosaga: Episode I – Der Wille zur Macht, is a Japanese-style sci-fi role-playing game that has many shared themes and gameplay components with Xenogears. The battle mechanism is similar to that of Xenogears (combo attacks, A.P. and E.P. gauges, and so on), but random encounters are avoided. Instead, the enemies are now visible, making battles avoidable. During the conflict, the player can make strategic decisions based on who will act next by seeing the few impending friend and enemy actions onscreen. A rolling slot moves with each turn, granting a bonus such as increased damage or bonus XP for any action taken. If the adversary is in a position to take advantage, the player can use a character’s boost gauge to cut in and act next, albeit foes can also boost, and enemy boosts always take precedence over player boosts.
Each character has their tree of ether spells that they can learn by spending ether points won in battle, with lower stretches necessitating the purchase of bits above them first. After purchasing a bit, as long as it does not need a unique talent of that character, the period can be bought and learned by any other character who can afford to pay twice the standard cost. Anti-Gnosis Weapon Systems can be outfitted with various weapons and attachments and utilized in combat if a character has enough A.P. on that turn to board their AGWS.
