Ok so here we go:
Akira tries to use blood magic to force Volkran into telling him what he had told Allura, in other words to tell the truth.
Volkran takes advantage of the situation and snatches control away from a weakened Akira, however he is put under the influence of the spell and forced to tell the truth.
Rather then actually repeat everything that he'd just said which could be potentially damaging to Akira's mental state, Volkran projects his & Akira's memories of the events into Allura's mind.
The instability within the vision was brought about by Volkrans failure to piece together the scattered memory fragments or to project the scene completely from memory.
The first scenario where there's no speech is because Akira didn't actually witness what happened this was merely a reconstruction of what he was told had happened.
The vision is Akira's home town, who took him in after he became a demon, 1 of the many shadow hunters (Their numbers used to be quiet large even though there's only 2 left now) went there knowing that they'd hide Akira if he went there, especially after how Akira became orphaned due to a demons attack, all Akira would have to do is hide the demon well enough to pretend, or prove that he was the same person.
Akira, after finding out what has happened discusses with some towns people that it's probably best he should leave, and that they should cooperate with his pursuers. Although this shadow hunter was also from the same town, Akira's teachings to his old town is that if the means justify the means in their eyes then they're doing no wrong.
Expecting the worst Akira hadn't gone far from the town and was regularly watching over it from a distance. The burning and destruction were the results of the blood magic, though using something so powerful drained a lot of his energy leaving him with barely enough blood to function. This hunter was also however well versed in clerical magic and had merely killed the towns people to instill fear in them to bring forth their cooperation following the use of revival magics.
I don't want to discuss the reasons for Akira#s actions as that may give too much away :P sorry the explanation is a bit long but hope it suffices.