Best way is to do 100 summon scrolls rebates, they give you most points value per scroll. If you are strong and active you can win enough summon scrolls from events to not even have to skip rebates or get many extra scrolls to finish them, it takes about 5 100 rebates worth of points to buy him from 0. So only quarter of time then to try draw him for 2k scrolls, which has 50% to be Kirin as well. Took me about 4 months from when i started going for him this way.