Terrah Horton is a character appearing in Solar Shadow 2. He is the true final boss of the game, fought in the Hidden Attic after defeating Ataraxis. He is the grandfather of Serenity Horton, Shinica Horton, Ilina Horton and Valerie Horton.
Sometime in the distant past, Terrah created the Curse of the Castle Masters, gaining fabulous powers and becoming the first Castle Master in the process. He used these powers to build the first iteration of the Lunar Soul Castle as a gift for Valkyrie Horton in 1995.
In 2011, he was defeated by Aidan Flamberge, who took over as castle master. After this, there were no records of Terrah for the next 11 years. It is possible that Shinica knew of his whereabouts during this time.
In 2022, he emerged to reclaim the castle. While he was away, the castle was destroyed and rebuilt three separate times, and the New Lunar Soul Castle now stood in place of the original. At some point, he challenged Eron Araia Armweak, the Castle Master at the time, and took away both her curse and her powers. He then stole one of Eron's prototype androids, 4ZC-1009, and placed the curse into her, so that it would not harm any humans, before installing her as a fake Castle Master through which he could rule.
Rather than appearing immediately on reaching his arena, he must be summoned by activating the two terminals in it.
Terrah has 450 HP, the most of any boss. He is divided into five equal phases, which are separated by brief monologues, and only really vary by their attack patterns. All of his attacks are red, similar to Andrea Yauman who uses blue attacks only and The Mossmouth who uses dull green attacks.
- Most characters appear as "???" in dialogue boxes if Selena does not know who is speaking, but Terrah appears as "!!!" instead.
- Terrah is not a Horton by birth but rather married into the Horton line and chose to change his name.