The lazy ninja is a Anemo character and before unleashing her might on the enemy you will first need to upgrade the character a little. Here is the complete list of the materials needed for Sayu.
Sayu Ascension Materials
Sayu Talents Upgrade Materials
Ancheladus is one of the World Bosses in Lost Ark. It can be found in the Feiton region and defeated by a large group of ideally well-equipped level 50 players.