Hello user Jirachi,
Thank you for the critique in my rate. I knew Tornadus-T received the Regenerator ability due to Black 2 and White 2, but I did not understand the mechanics of Stealth Rock + Regenerator. I just did the math and found out that it does in fact make a difference--especially in 300 HP's favor. After taking 8% (due to Regenerator minus Stealth Rock) multiple times, it's left with 12% as opposed to 299 HP's 11%. 1% can make a different in a low-high role situation. Thank you for the information. However, in my rate, I did say that the 4 HP EVs allows 4 Stealth Rock switch-ins in Thundurus-T's case only. I suppose I should edit it anyway.
Sincerely,
Your friend Gimmick