Monk Maz Koshia is a character and boss in The Legend of Zelda: Breath of the Wild. He is the primary driving force of the main quest "EX Champions' Ballad", unlocked after installing the "Champions' Ballad" DLC pack. As a boss, he is fought inside the unnamed Divine Beast during the Final Trial. Link has to defeat Monk Maz Koshia to obtain the Master Cycle Zero.
After Link frees the Divine Beasts, Zelda speaks to him, telling him to return to the Shrine of Resurrection. Upon his arrival, Monk Maz Koshia speaks, beginning the trial. The monk grants Link the One-Hit Obliterator, guiding the Hero of Hyrule to four Shrines at the Great Plateau and solving the trials within.
Upon the Shrines' completion, the One-Hit Obliterator shatters, scattering towards monuments all over Hyrule. Monk Maz Koshia orders Link to travel to the monuments, participating at the Champions' trials and engaging in rematches with the Calamity Ganon's Scourges. When Link completes these trials, Monk Maz Koshia directs Link back to the Shrine of Resurrection, where the Final Trial awaits.
Link navigates the Final Trial, unlocking four locks that lead to Monk Maz Koshia's throne. Once the locks are unsealed, Link goes to Monk Maz Koshia, where the monk challenges Link to a duel. When Link triumphs, Monk Maz Koshia grants Link the Master Cycle Zero, and disappears into the afterlife. Link can challenge Monk Maz Koshia to a rematch by returning to the Final Trial.
Monk Maz Koshia is the final boss of the Final Trial ending the "Champions' Ballad" quest and DLC, and is fought in four phases.
Monk Maz Koshia boasts a wide array of tactics that he may use in his fight against Link. Like a Yiga Footsoldier, Monk Maz Koshia can magically teleport and strike Link from above with his sword, or he may use a bow and shoot at Link from the air. Monk Maz Koshia can use Fire Arrows, Ice Arrows, and Shock Arrows to strike Link. After Monk Maz Koshia's health has been reduced by a quarter, he will retreat and split himself into nine copies. Each of these copies can damage Link, although only one of them can sustain more than one hit. In order to advance, Link must find the real Monk and attack him. The copies will work in unison to attack Link, until they are destroyed. Once all of them destroyed, Monk Maz Koshia may summon another set.
Once Monk Maz Koshia's health has been reduced to half, he will retreat again and magically enlarge himself while flying in the air. At this stage, Monk Maz Koshia can use charged beam attacks to strike Link. If Link deflects one of these beams back at Monk Maz Koshia, the Monk will be temporarily stunned, allowing Link to attack. Monk Maz Koshia may also summon a series of eight metallic, spiky balls. Monk Maz Koshia will sequentially cast these balls at Link in an attempt to hurt him. Afterwards, Monk Maz Koshia will begin charging a Lightning storm, which will strike each of the metallic balls. Much like with Thunderblight Ganon's metal spikes, Link can use the Magnesis Rune to direct one of the metallic balls near Monk Maz Koshia, causing him to be struck by his own Lightning. Monk Maz Koshia can also magically tilt the battle stage before summoning the metallic balls, which will roll towards the bottom of the slope before falling off. Monk Maz Koshia can also stomp the ground to cause a tornado to chase Link around. If Link is hit by the tornado, he will be struck by a strong pulse from the ground.
At some point, Link can ground Monk Maz Koshia. If Link gets close to Monk Maz Koshia's feet, the Monk will stomp the ground, damaging the Hylian Champion. Monk Maz Koshia can also summon two miniature copies of himself, who will attack Link in a similar manner to the second phase of the fight. At any time during the fight, Link can distract Monk Maz Koshia with Mighty Bananas, handy in exposing the real Monk during his second phase.