If you are below lvl 70, DON'T SPEND SEALS SCROLLS AND SAVE FOR KAGE TREASURE. Like what Dosu said, you'll pull solid common and rare characters. Kage treasure will help you build a decent team. If you go online everyday for about a month and half, you should have be lvl 70 and have access to kage.
In most treasures (excluding Jin and Edo Treasures), you get a common for every 10 seal scrolls you use and a rare for every 60 scrolls you use. You can pull 1 by 1, pull 10, or pull 60 at one go and still get a character.