Learn dancing demon spear! Don't have to use it though lol. But it's up to you, upgrade now and leave it first or upgrade all at once and watch your precious sp decrease

If you learn it now you'll nvr see your sp really high at all though. But definitely, learn the second book of dancing demon spear. It hits the enemy twice, each time more than an average hit, and then a normal hit follows soon after. As for soul spear truth, don't learn cos it sucks... just kidding it's really good. Learn it when you can, but NEVER go 0 lvl difference, cos that's just gonna make you have not enough sp to last you through all your later lvls. And make sure you learn flying dragon flow. If you have enough sp, learn that bloody fan storm skill and show it off to noobs. They'll think it's cool

. Of course, just learn the first lvl and don't increase the lvl anymore after that. Chain Spear Tiger is also good, each hit less than average hit, but the last hit is really strong. And don't forget to learn the passive skill of Heuksal which increases HP. I'm not so sure about Wolf bite though. Yukon spear may be good. I'm not at that lvl yet and my brother didn't learn that skill either. And yes learn Chain Spear Naru(did I spell that right?), the last book of Chain Spear series. That's basically the skills you need to learn. Soul spear series learn everything, Ghost Petal learn everything. Oh yeah and don't forget to charge up before using flying dragon flow.