Most of your poke is through the usage of your Q or grenade. Each minion waves come in 2 rows of 3 except for the cannon waves. Your grenade can bounce a maximum of 4 before disappearing. Meaning you can drop your grenade on the row of minions of which the opponent is closest to or between.

This ability is just a long beam until you or your allies damage the enemy in some sort of way to trigger an icon above their head. Your W or beam can root anyone who has this icon and it can be useful to stop someone from running away or help an ally run away. It is also used to give you an opportunity to auto your opponent or delete someone at a distance that is already low.

Your Lotus trap or E can be used for multiple purposes. In the mid lane, however, you want to place them in bushes or openings where the jungler could come out from. This allows you to avoid ganks since you can root them at that spot and run back to your turret. You can also place it in an area where you want to escape to since the lotus trap slows anyone that walks over it. These traps can be used as sensors for champions that can turn invisible like shaco, twitch, pyke, or everlyn. It has a passive call Beauty of Death where every person you kill spawns an activated lotus trap. There are times where a kill will lead to another kill without you knowing.

you ultimate has a long cone range that can fire 4 burst shots. To fire each shot, you need to press R while aiming with your mouse. While your ultimate is activated, you are completely immobile until firing all four shots or deactivating it. Each shot comes with a slowness effect that you can utilize in certain scenarios. You generally don't want to use your ult unless you can kill the enemy in 1-2 shots due to the possibility of missing or them escaping (Flash Summoner Spell). One of the best usages of your ultimate is stealing dragons, baron, or herald due to being in the mid lane which is so closest to both.

Your passive allows your fourth shot to critically hit with additional damage, including your ultimate. Every time you critically shoot, you gain a burst of movement speed. Useful for poking with your fourth shot and running away. Great for late game when you have 100% critical and you are just running around and autoing. You have 4 bullets for each round before reloading and you fire at a fixed rate .

You truly do not want to use your ability to clear the lane unless you have to like when defending against multiple people, when the wave has crashed into your turret, or when your laner is in a different lane so you have to push hard. Your main source of damage is your autos so you can easily last hit or clear minion waves without using any mana. Reserve your mana only for fighting, saving, prepping, or stealing. When the minion waves are coming in a line before clashing with your wave, you want to use your W or beam. For big waves that are already piled up, you want to use your E or Lotus trap. Your Q is generally good for all purpose wave clearing. When You have extra shots left from your R, you can use it to clear lanes.