Since your pacheon is at 47, you can get your ice up there too. Don't raise your masterys above that if you want to gain more sp.
A big misstake alot of people do is to train on too high leveled mobs.
Stay at the ones you can more or less 1 skill. The extra sp you get from a higher level mob isn't worth the extra time it takes to kill it. So at 50 mujis/ujis seems alot better for you. Try it out, I have myself been around alot of mobs trying to find out where I can get most out of my time. As long as you don't have a sostar or better, the mobs just below your level usually works best.
Shades have the nasty habit of being ranged and stationed. So unless you 1 hit them, they will always get atleast one hit on you except when you freeze them with your ice. Mujis/ujis on the other hand have to run up to you before they can start to attack and you will probably kill them before that. You will save pots and also get more drops, since you'll kill alot more mobs when they are lower in level.
With the gap you have now it will take you from lvl 50 to about lvl 53 before you reach 10k sp. That is if you stay away from quests and keep your masterys at top 47.
If you only have pacheon an ice, that will cut down alot of the required sp. But I doubt 10k will be enough. Do maybe 2 more levels keeping your masterys at 47. Will more then double those 10k.
Take a look at this chart. Really good for calculating what sp you'll get
SP gained per level and gap