Repeatedly destroying the shell of the Eye of Time was the first step, because it might not look like it but the Eye was losing energy, and before long it would not be able to maintain its presence inside this domain.
The method Rowan was using to achieve this effect was ingenious, but it was also a loophole that the Eye had left open, in case Rowan followed this path.
Before long the body of the mortal was a shell of itself, and it was on the edge of dissipation, but Rowan did not let up his assault, he knew that even if he dispersed the shell of the Eye of Time, it would still consider it a victory. It would most likely wait a few months to even centuries before it contacted Rowan once more, and it would be assured that by that time the seeds of greed and doubt it had planted inside his mind would have germinated and festered.