Yggdra Unison is a real-time strategy game for the cellular phone and Nintendo DS, developed by Sting Entertainment as a "fandisc"-type spinoff to Yggdra Union. The original cellphone version was self-published and released on November 11, 2007; the DS version was published by Atlus and released on December 12, 2009. Neither installment has been released in any language other than Japanese.