lvl 100 Base stats without any rings/armlet 168 agi, 165 offensive, 185 summon
with flame set/1 snow ring/ a greater soul accessory you should have 197 agi
Offensive skills: maxed out ether blaze, heavy shot, overlimit, mana drain
summon: lvl 6 unlimited force, lvl 10 patience, lvl 1 life spirit, lvl 1 war battler, lvl 10 battle barrier, lvl 1 destroyer, lvl 10 peel off
passive: lvl 10 ether weapon, lvl 10 range

I'm sure there are a few things that can be tweaked but this is the build I came up with by thinking about the play style of a valkyrie.

Take it as you will, its just a reference guide.

Note that for lvl 8 patient (defense buff) you need 155 summon and for lvl 10 patience you need 185. It's a toss up, 30 more agility or 60 more defense. Although if you have lvl 8 patience you can put those extra 2 points into unlimited force. Unless that extra 60 defense gets you above the defense threshold, I would get the 30 more into AGI and 2 more SP's into unlimited force, but that's just me.

Cheers