Whoo~ More Shadower Build Questions!

i maxed shield mastery over flare. With Shadower's avoid, you'll most likely do misses when soloing bosses anyway. BUT you could also just to 20 flare for party killing (though most people don't like summons during boss runs). I don't use it, i forget about summons often, so i didn't max it.

As for 4th job:

at 120 i did 1 venom, BS, and shifter. 1 venom is plenty enough for the entirety of your shadower career (it really does suck now). 1 shifter is already godly and BS for obvious reasons.

i proceeded to max BS with a funsies point in mesos mastery, and assassinate. after BS i went with mesos mastery and anm now doing Shadow shifter. IDK what the hell to do next. Taunt or assassinate maybe?