Ok so let's say that you put it on someone vs a mage team, they won't be able to cc you for 15 secs, then after that the mage is like'' finally sac is down now i can cc pala!'' , jk another sac. Being unccable for 30 seconds is even more broken than frostbomb in the beginning of mop.
Hand of Sac is on a 2m cd. It wouldn't be ridiculous at all.