Yhwach

He is the leader of the group known as the Vandenreich.

Appearance
He has long dark hair which reaches past his shoulders. He has thin eyebrows and his sideburns extend most of the way to his nose, but he is otherwise clean-shaven. He wears white trousers which are mostly covered by a long white coat with large buttoned cuffs. Over this, he wears a black cloak which reaches down to the ground. He wears long white boots which have two rows of buttons on the front.

Personality
He claims to dislike arguments and brutally stops rows between his subordinates. He does not value his subordinates, wounding and even slaying them when he deems them to have fulfilled their use.

History
At some point during the seventeen months after the defeat of Sōsuke Aizen, the Vandenreich invaded Hueco Mundo, and he personally defeated its ruler Tier Harribel. As a result, he imprisoned her and claimed Hueco Mundo as the territory of the Vandenreich, as well as another foundation stone to invade Soul Society.

The Thousand-Year Blood War arc
When Luders Friegen returns to the Vandenreich base, he starts a row with Ivan Azgiaro. The leader severs Luders' arm, complaining that he dislikes arguments. Luders struggles to his knees, declining the leaders offer to allow him to lye down before him. He states that five days is required for both them and Soul Society to prepare for the battle. This prompts the leader to question if Luders is a prophet. When Luders denies this, he asks why Luders is talking about the future. He attacks Luders, resulting in a large amount of blood flying into the air and promptly turns his attention to Ivan, telling him that he has no reason to praise or blame him and that he did enough to slow down Ichigo Kurosaki. While pointing at him, he tells Ivan that his job is finished and that he can become a foundation stone to build peace. As Ivan erupts in a torrent of blood, one of his subordinates asks if that is alright as Arrancar should be precious due to not needing to be taught how to fight. He dismisses this, saying that he can acquire as many Arrancar as he wishes. He states that Hueco Mundo is already their territory and looks at the imprisoned Tier Harribel.

One of the Vandenreich members picks up Ivan's medallion and examines it, noticing that it was used but Ivan was unable to seal Ichigo's Bankai. The Leader states that they need a special plan to seal it. The Leader states that "hotblooded fools" can be useful at times and orders him to instruct the 'Jagdarmee' of Hueco Mundo to collect "a few idiots" alive.

Powers & Abilities
Immense Spiritual Power: According to Kirge Opie, the Vandenreich Leader has strength paralleling that of an Espada, as he was able to defeat the Third Espada Tier Harribel without much difficulty, while the former Espada could "do nothing in front of him".

Quotes

 * (To Ivan Azgiaro and Luders Friegen) "How many times do I have to tell you? I will tolerate no petty bickering in my presence. Conflict does not please me."