I got 2 riven for this weapon and searching, i learned that this one was not the more damage, the second in fact, but the more crit. So i had a look on existing builds and find nothing interesting.
Here is a build quite better than other here and i have not finished to up the weapon.
Only one format and not so bad on a [Valkyr Prime] or [Atlas Prime]. Try it with others.
A little fun is always welcomed.

Here are my stats as it seems that total degats is not the same
Total degats : 3079.2
ground 12316.8

i don't use heavy attack so... you have this build
on [Valkyr] that really rocks !
Have fun

NB : more to come with 2 umbra that can up crit chance to 116.3%