If you recall, Rand combined saidar and saidin into a pure, combined form of the One Power. That is likely what he is can use now, basically just bending reality itself. To pull the quote from the book, "He wove something majestic, a pattern of interlaced saidar and saidin in their pure forms. Not Fire, not Spirit, not Water, not Earth, not Air. Purity. Light itself. This didn't repair, it didn't patch, it forged anew. With this new form of the Power, Rand pulled together the rent that had been made here long ago by foolish men."
At least, that's my guess.