Army of Darkness/Xena Warrior Princess: Why Not? is a four issue crossover from Dynamite Entertainment released in 2008.
The Wise Man from 1300 AD comes to the 21st Century to tell Ash that one of his Mini-Ashes from the windmill found a mini-Necronomicon and accidentally fell into the Xena Universe, where he used his 21st Century knowledge to make technologically advanced weapons to terrorize the locals. Ash goes to Xena's Universe and meets Xena herself and her sidekick Gabrielle. Xena and Gabrielle are captured, and Ash runs into Autolycus, whom everyone believes is the evil Mini-Ash. Autolycus and Ash rescue Xena and Gabrielle and defeat the evil Mini-Ash. Before Ash returns to the future, Gabrielle asks him what wonders are in the far future since they won't live to see it, so Ash builds a S-Mart for the inhabitants of Xena's world to enjoy and if anything goes wrong there to blame it on magic.