Not sure the affects, really not sure on the stats offhand. Somewhere in the neighborhood of like ten+ yrs each, and I was wearing two. As for permanent affects, don't quote me, but logically I had a base age of 25 no matter how many times I had worn them. My math might be majorly wrong. 25 (age base) + 25 (two rings roughly) + x (power of a wither). I aged died for good, at 64 hours of play, at roughly over 50yrs old. Hrm... And I thought rot was powerful.