Taurus Ballista, the Buffalo Lord, is one of the stronger Lords, armed with the Supremacy Torreana.
Ballista embodies the Lords' purpose, which is to purge the world of any human with special abilities, for the own good of humanity. However, Tsukasa tells him that they do not need someone to protect and limit humans and the Lord is destroyed by the teamwork of Decade, Agito, and Yuusuke in the G3-X armor.
Later, in episode 30, a copy of Taurus Ballista was recreated by Super Apollo Geist by combining Lords. This copy of Ballista is destroyed by Asumu.
Taurus Ballista is capable of human speech, like an El Lord. He's also shown to command Ant Lords, including Formica Pedes troops and a Formica Regia. Taurus Ballista is also able to release cross shaped energy blasts from his Supremacy Torreana.
Curiously, his special abilities, like the energy blast and transport, rather than being associated with the same sacred symbol used by the lords from the original Agito series, actually are associated with a cross.
Kamen Rider Decade: All Riders vs. Dai-Shocker
A Taurus Ballista is seen leading a group of monsters advancing towards Tsukasa, after his encounter with Joji Yuki (A.R. World). Tsukasa, awakened by Joji Yuki's words leaves the place to face Dai-Shocker, while that version of Joji Yuki is shown for the last time getting ready to fire at those monsters. The result of that battle isn't shown.
Kamen Rider × Super Sentai: Super Hero Taisen
Taurus Ballista was part of the Shocker-Zangyack Alliance, appearing among the army of monsters in the final battle against Riders and Super Sentai. During the battle, Taurus Ballista doesn't receive any highlights, although he can be briefly seen being pushed away by Red Racer, from Carranger, in the background of the first aerial group shot of the battle.
Kamen Rider WizardTaurus Ballista was one of Amadum's human-turned monsters in the world within the Magic Stone. He appeared with his friends listening to Amadum's broadcast that the 13 Rider Rings had been stolen. They turned their attention to where the young boy and girl were staying, assuming their intimidating monster forms before Rinko told them to back off.
Taurus Ballista was later part of the group of monsters that tried to capture the boy and girl along with the Rider Rings they were carrying. They ended up fighting Kamen Riders Wizard and Beast, who also intended to take the Rider Rings to prevent the monsters spilling out into the prime world. The boy proceeded to summon Hibiki, Kiva, and Den-O, then Kuuga, Agito, and Blade to fight both the monsters and Wizard and Beast. When the children called to the sky for help, Kota Kazuraba heard them and appeared in their world as Kamen Rider Gaim. He proceeded to take on all the monsters by himself, finishing them off before introducing himself as Gaim.