Chair-sama

Chair-sama was a nigh-godly chair that Sosuke Aizen was bound in for two years. However, its divine existence was shattered by Yhwach.

Appearance
Chair-sama was a large golden chair resembling a throne. It had three slim rectangular pillars on the top that Aizen rested his head on, as well as long rectangular armrests. It was also covered in the bindings that restrained Aizen.

Personality
Chair-sama was very patient and resilient, as it spend two years in Muken listening to Aizen recite various keikakus without complaining. It tirelessly served the Gotei 13, not being forced down by anything until it met its match. Chair-sama, during his time of existence, liked Aizen very much. Aizen however did not, as his attempt to break it through Hado #90 Kurohitsugi.

Abilities and Powers
In terms of durability, Chair-sama was one of the most powerful objects in the universe alongside Yhwach's horse, Horse-sama. It was able to withstand Sosuke Aizen's immense Reiatsu without even taking a scratch. However, it met its match when Yhwach blew it to smithereens without any explanation as to why.

Fake Karakura Town arc
After Sosuke Aizen was defeated, Chair-sama took on the noble task of restraining him. It and Aizen were transported to Muken to be imprisoned for 20,000 years.

The Thousand-Year Blood War arc
Two years later, Aizen was freed by Shunsui Kyoraku, and Chair-sama accompanied him to severely restrain his power. Aizen performed some displays of powerful Reiatsu to help the Shinigami, but Chair-sama was unaffected. Chair-sama was left with Aizen in the Seireitei as the Shinigami advanced to the Royal Realm. Some time later, Yhwach came to the Seireitei and destroyed Chair-sama, freeing Aizen.