Here's what I think.
Zorua is Zoroark. When Celebi time-travels to the future, we see Zorua has evolved into Zoroark. Its trainer, I bet, is the villain (since one of the henchmen acted like they knew who Zorua was), and he is using Zoroark's ability to change into the beasts to attack the town. He obviously wants something, but who knows what. Maybe Celebi, maybe Ho-Oh - who knows. Maybe the trainer and Zoroark lost their way, and Zorua will remind Zoroark of what it once was or something cheesy like that. Then at the end, Ho-Oh will have gotten Celebi's phone call and will come to stop these illusionary beasts damaging the rep of its real creations! Though since Zorua is also angry at Celebi from one of the translations posted a while ago, this whole theory might be totally wrong.