This happened to me a while back but when I was in the Battle Tower on Platinum my Togekiss got hit with both Thunderbolt and Ice Beam on 2 different occasions and neither came in as Super-Effective and didn't do much damage. Also on PBR, I was doing the 100 win challenge when it happened again. It got hit with Ice Beam and it didn't register as Super-Effective or do much damage. I bred and raised this Togekiss myself so it wasn't traded to me and I don't use AR or any other cheating devices. Has anyone else experienced this?