Like the title siad we are talking about the scroll that suigethsu found.I have a theory what if the scroll that suigethsu found is the one that naruto used to train kagebunshino jutsu in the first chapter.The scroll naruto took at that night was used originally by first hokage and it has forbidden seals. Mizuki was brain washed brain washed by orochimaru and oro would have said that if he(mizuki) gives him scroll of forbidden seals he will give him nice position in sound village.But Mizuki failed.Then at chunnin exam he(oro) would have get hand on these scroll. Oro would have learned the secrets of that jutsu and summarised in to a small scroll (in naruto first chapter the scroll of forbidden seals is big scroll).
My assumption is that the scroll of forbidden is have a sealing jutsu that used to seal the human who know everything. Thats why in first chapter when naruto took the scroll every one said that it is a dangerous scroll.The human who know everything may be so6p or His first or second son or the hashirama himself.
what do u all think about it?