Theres a summon rebate once a month, which awards 25 pulls. With active play, doing all dailies and redeeming summon scrolls at least once during any event during month it's safe to assume you get 100 scrolls monthly. Did that 3rd month in a row, without spending cp directly on scrolls, so i can vouch for that number. Multiply that 100 (125 if always using rebate) by the age [in months] of your server, add to that age of ur server in days (free draws every 24h) and more or less here's your total pull count. Asuming 125+30 per months, it takes 13 months+ without spending anything on scrolls to get super rare, if we assume he is on exactly 2000th pull.