The Tidewalker sect is a group of sacred beasts on an unnamed water madra path. They are located somewhere in the Trackless Sea, perhaps near the north shore of the Blackflame Empire, but this is not clear
" From the glimpses Yerin caught, they had leathery blue-gray skin, gills working at the sides of their necks, and shark teeth; sacred beasts advanced enough to take on human form. "
― Uncrowned, Location 2347
The Tidewalker sect was one of the six factions under truce at the pocket world, Ghostwater. The Tidewalker's chosen representative, their young prince, did not arrive prior to the destruction of the pocket world's main portal.
At the Tournament
The Tidewalker sect was present at the 18th Uncrowned King Tournament. Under bribe by the gold dragons, a group of Underlords, including two Tidewalkers, launched an unsuccessful attack on Yerin Arelius, Eithan Arelius and Naru Saeya during the second round of the tournament. During the fight, the Tidewalkers demonstrated the ability to form bubbles of dark liquid madra, which could be used either as a Striker technique or a defensive shield. The pair also displayed a Ruler technique which manifested as a serpentine dragon made of water.