User blog comment:Xilinoc/Ch. 538 Standing On the Edge/@comment-1332195-20130523193325

Sorry to delve into other manga, but in Naruto, the Great Toad Sage is also referred to as Ojiji-sama or 'Great Honourable Geezer' (大じじ様, Ōjiji-sama) according to Narutopedia; He is also referred to as Giant Grandpa Sage (デカじいちゃん仙人, Deka-jiichan Sennin), so people's conclusions that Big Bad Rug's Sajin grandad look like a fairly solid guess at this early point.