Building / Built a tank, advice suggestions appreciated.

[DarkDisciple27]

So it is a magic-light campaign for the most part. I am building a tank based on hexblade / kensai to get mettle and withstand. Also going to grab steadfast determination and con will be my primary stat.

My starting stats:
str 12/17 (1)
dex 13 (1)
con 17 (3)
int 14 (2)
wis 9 (-1)
cha 17/12 (3)

I can't decide whether to make cha or str the good number. I will be heavily invested into diplomacy and intimidate, not to mention arcane resistance and the goad feat. On the other hand hitting things better is nice.

This is the planned build through lvl 15:
hex 1( 1): hexblade's curse, combat expertise(feat), weapon focus (longsword)(feat)

hex 2( 2): arcane resistance

hex 3( 3): mettle, endurance(feat)

fig 1( 4): +1 con, shield specialization(feat)

fig 2( 5): shield ward(feat)

ken 1( 6): signature weapon, steadfast determination(feat)

ken 2( 7): power surge

ken 3( 8): +1 cha/str

ken 4( 9): ki projection, goad(feat)

ken 5(10): withstand

fig 3(11):

fig 4(12): +1 con, blind-fight(feat), dodge(feat)

fig 5(13):

fig 6(14): mobility(feat)

hex 4(15): dark companion, elusive target(feat)

What are your thoughts on what I have planned, and where would you go from lvl 15?

Thanks for any advice!