Every 60 rolls you do in a treasure that has him in you are guaranteed to get or 1 or 2 fragments, so in the best case scenario you get him with 2400 seal scrolls, in the worst-case 4800. The average is 3200/3300.

There are the free rolls in the other treasures. Every 4 months of free rolls you get 1 or 2 fragments from every treasure he is in.

So lets say you play since 7 months and you are level 70 since the 3rd month, then in average you got 8 fragments from the free draws. The 1100 scrolls (if free draws are not included in the calculation) gave you the other 29 (1100/60*1.5 = 27.5).