I'd say pull in GNW treasure, not only they have better rare that are gonna last for a long time but also that treasure has the best common 10 pulls ninjas. Since you are not gonna get a rare anytime soon with just 20 seal scrolls, it's best to rely on those common ninjas in GNW treasure. I also suggest you stay with mb in the worst case scenario when you pull not so good ninjas. Around your current level MB, Kimi, Sasuke, Iruka work wonder up until 75-80. You don't even need initiative to use that line up, all you need is primary stats.