i was able to trigger this item glitch by equipping a personal item to a character (and the guy was in the background, not active). i think the one he wearing before it was Mandarin's Ring, and the character next to him had the +2 body/focus/strike item. I removed the item or something and noticed it had gotten the "+35% energy power damage"
This was the first time i had equipped a personal item.
The first time i had gotten this glitch, it happened to a ton of items, and i do recall putting personal items on several characters during that period.. it was the first time i was seeing +3 to powers so i started equipping them.
so i think the glitch involves equipping a personal item. then....?