I am going to try and make these guides as short as possible with a decent amount of information to understand the build. This way you can get to play faster! I will try to update the guides as needed. If there is interest, I will post more.

I am Opti#1513 on b.net so feel free to add me if you need any help, have any questions, or just wanna play some HoTS together!

Kerrigan

This really is a good build for roaming thru the map assisting teammates when needed, it's really built around being more useful in team fights as well as soloing objectives/camps. The thing to remember with Kerrigan is, try to save your Ravage for when an enemy is within killing blow range. Most people take Sweeping Grasp for the first talent, which is viable for trapping. But I have found when roaming/ganking the siphon is much better for me as it gives added sustain. with Siphoning Impact you could easily turn your retreat into a takedown by using your Q-W-E combo on someone who is chasing you.

Early Game: If you take nothing at all from this guide, at least remember one thing; KERRIGAN IS SQUISHY EARLY GAME, PLAY SAFE! You have the ability to put out very good amounts of damage the entire game, but if you aren't careful, you will get killed.v Soaking is important, getting kills really early in the game is good for intimidation, but other than that its not going to benefit you too much. If you want to get some early kills tho; Nazeebo Jaina Raynor and Malfurion are good heroes to take down early on.

Mid Game: Stay with your team as much as possible. Hide in bushes or flank to kill unsuspecting enemies when they are low on health. Make sure you are helping with all camps and objectives. This is also a good time to roam around the map looking for heroes that are out of place. For example; a Brightwing is trying to get caught up to the rest of her team, get in between them and pick her off so she never even makes it there. Raynor is hanging out behind his team? Go around behind and take him out easily.

Late Game: This is really where you can roam around solo looking for enemies and taking camps/objectives. You don't need to be with the team as much now, but you still need to be involved in every teamfight. By this time your Basic Attack will be buffed up enough that you can save your Q-W-E for enemies escaping. You should be able to 2v1 3v1 heroes that are 15% or lower health with ease. Instead of the standard Q-W-E combo, let them start to group up on you, pop down your Impaling Blades then use your Primal Grasp to pull them in, now use your Ravage to clean up what is left of your enemies.

Using your MAELSTROM properly:
If you are 1v3 or more and the enemy heroes are over 15% health, don't try to pop your Maelstrom thinking you can take them out. You will fail most of the time. However, 1v3 and they have 10% or less health, try to activate it just out of their reach, then leap to the lowest non tank hero in the group. Make sure you are still landing your spikes and rakes properly while in Maelstrom. It can be devastating to the enemy heroes.

Other Tips:

Just remember that Kerrigan is fairly squishy so don't get too greedy and try not to take on heroes such as Arthas, Muradin, Diablo, Tyrael in a 1v1 situation whenever they have full health.

Make sure to communicate with your team so that you are focusing on the correct heroes. Your attack priority should be: Healers > Supports > Assassins > Tanks. Never NEVER focus on tanks in large team battles unless you catch them low and can Ravage them or Primal Grasp them back to your team so they can finish them off.