Li Li commonly used as support since she can heal amazing amounts of health has another role that isn't used as much as the other, but this other side of Li Li can deal great amounts of dmg, at the cost of not being able to heal the same quantity.

There are a couple ways to make this type of Li Li work, let's see.
Talents:
Lv1
Conjurer's Pursuit: I don't find this very useful.
Pro Toss: Not useful since we are going dps.
Timeless Creature: Useful in case you want to focus your build in Cloud Serpent.
Gale Force: This is the one that i preffer, since you will hit 4 enemies instead of 2 at lvl 4.
Lv4
Healing Ward: Not useful since we are going dps.
Mending Serpent: Not useful since we are going dps.
Mass Vortex: This is the one we will pick, +2 hit = +dps
Lingering Blind: I kind of preffer the last talent.
Lv7
Shake It Off: Could be useful, at the cost of some dps.
Pitch Perfect: Not useful since we are going dps.
The Good Stuff: Not useful since we are going dps.
Lightning Serpent: This is the one i preffer, even if it is not much dmg, it will be a bit more when you pick Serpent Sidekick at lv16.
Lv10
Jug of 1,000 Cups: Not useful since you are going dps.
Water Dragon: This will be our ult.
Lv13
Elusive Feet: Could be useful for some extra def.
Hindering Winds: This is the one that i usually recommend, some slow is never bad.
Surging Winds: This isn't very usefull unless you pick Kung Fu Hustle at lvl 20, if you do so, combine both talents, and you will have almost-permanent +20% ability power.
Shrink Ray: There are better choices instead of this one.
Lv16
Safety Sprint: Could be useful for running away, still preffer the other choice for extra dmg.
Two For One: Not useful since you are going dps.
Herbal Cleanse: Not useful since you are going dps.
Serpent Sidekick: 2 Cloud Serpent instead of 1 doubles the dmg of this ability.
Lv20
Jug of 1,000,000 Cups: Not usefull since you are going dps.
Double Dragon: Double dragon, double dmg.
Kung Fu Hustle: If you plan to pick Surging Winds at lv13, pick this one, you won't regret it.
Storm Shield: You are not support, but in case that you need to help your team, this is always an extra shield, but remember, a good attack can be a good defense.
Bolt of the Storm: