The Sword of Etheria is a 2005 hack and slash video game that includes loose elements from the Oz series created by Konami for the Playstation 2. It was first released in Japan under the name OZ (Over Zenith) and in South Korea as Chains of Power before its 2006 release in Europe. The game has never been released in the US.
The game takes place in a universe where humans, gods, and other spiritual beings called "Katenas" coexist. Three of the Katenas chosen by the gods are referred collectively as "Oz" as they investigate the loss of the planet's energy source called Etheria. It turns out that the gods seek to destroy humanity by consuming light and cast certain parts of the world into darkness for centuries.
When one of the three disappears, they set off without him. Fifteen years later, they come upon a boy named Fiel/Feel whose village was attacked by monsters called Volo and another group of katenas. They have kidnapped his sister Dorothy and it is up to them to rescue her while facing danger and obstacles from the gods. Fiel gets his powers from his cat named Toto who happens to be able to transform into a "Lex". The names of these characters apparently are the only Oz references.