Knight of Cygnus: Soul Master

would it be smart to make soul blade 21 b4 i do mastery and booster?

Some people do it, but I wouldn't suggest doing that unless your grinding with 4x from level 30 - 50.

If your planning on CPQing from level 30 - 50, get mastery first.
Why?

Reason 1.
130% damage + 60% mastery > 180% damage + 10% mastery.
Sure, soul blade is a ranged attack, but remember, it only hits 5 monsters opposed to slash blast, which hits 6 monsters. Also in CPQ, all the monsters are mobbed up together, so Soul Blade wouldn't have an edge over slash blast, Sould Blade would be doing crappy damage to 2 or 3 out of the 5 monster it hits due to the 10% mastery.

Reason 2.
Some people seem to forget that Mastery also gives accuracy.
As a dexless Dawn Warrior/Soul Master, I find that 19 accuracy VERY life saving, as I don't get my zhelm, dex PAC etc. until level 50.

Reason 3.
People say that training with soul blade is more efficient than training with Slash blast, which is true.... only if your killing the same kind of monsters.
If you wanna go to truckers at level 40 for EXP heaven without having to use a crappy maple sword, get mastery first.

You would need around 96 accuracy to train at truckers.

Unless you have godly dex equips, low dex/dexless warriors won't reach 96 accuracy without mastery.