NOTE: I use this build specifically for wrathful advance (and level cap--ez 1k+ kills). I don't use [Kullervo] specifically however, and run [Thalys] with my [Citrine] (WA subsumed on her 4)
Edit: Citrine Build

Ev 2: Dreadful [Reach]
With dreadful [Reach], if you get the full 20 stacks, it's practically another 2 more meters for your range. If utilized fully, [Thalys] attack range in incarnon form should be around 10.8 meters.
Choose any of the other 2 options though if you're bothered by the attack speed or if you don't have arcane strike equipped.

Ev 3: Echoes of [Rage]
+1 combo count on shard damage. Makes it easier to gain combo when attacking.

Ev 4: Swift Transmute
for obvious reasons, 3x combo to activate incarnon form instead of 6x

Ev 5: Chain Shatter
This is a heavy attack influence build. Chain shatter's evolution detonates shards with a heavy attack, and any nearby shards will also detonate within blast radius.

SHORT BUILD EXPLANATION:

Because this is a heavy attack build, I slotted in [Killing Blow], [Amalgam Organ Shatter] and [Melee Elementalist] (instead of [Galvanized Elementalist]) to drop [Thalys]' heavy attack wind up speed from 2 seconds to 0.71 seconds. Because I don't have [Galvanized Elementalist] equipped, it made better sense to slot in [Voltaic Strike] instead to help bump up the low status chance. Of course, you are free to do whatever with your build and can slot it in instead if you prefer having more status chance over the extra 60% heavy attack wind up, which would raise it from 0.71 to 0.91 seconds instead (which is still better compared to the base 2 seconds wind up speed). You can also replace [Voltaic Strike] with [Shocking Touch] if you want more damage.

If you choose to slot in a riven, however, (not recommended at the moment because of the low disposition, but unless you're insane like me...) try getting a CD Range -nonharmful neg for your roll. You can also choose to slot in something else for Galvanized Reflex--I only use it so I can instantly activate incarnon form whenever I'm doing level cap.

[Dreamer's Wrath] could also maybe be changed into [Dispatch Overdrive] now that I think about it.