Conjured armor. The concept of being able to don magical armor at a moment's notice was a fantasy of mine.It  never properly worked in my first life. There was usually a missing piece or would only last for minutes. It needed to possibly last the day through countless skirmishes. It would also need to withstand blows from magic and mundane damage. In the end, it was  scrapped for the time being. Maybe I could fix an old problem with modern solutions.