Hello! I am SiXtYnInE and I would like to tell you on how I play better with the merc Sparks!
I have been playing Dirty Bomb for a few days now and I have grown to play a lot better with Sparks in those days!
By no means am I telling you to follow these tips. I am just giving advice to anyone who is thinking about getting sparks or has sparks but is still learning how to play with this merc.
Take this into consideration:
Sparks is a medic with low heath, very high speed, and very high support.
Sparks’s health packs are little and only give 30 HP.
Sparks’s weapons lack in damage. (Her knife and cricket bat are the same as any melee weapon)
Sparks’s Revivr is a long ranged weapon and defibrillator.
Ok lets get this started. 
Speed:
What you are going to need is to be aggressive (But don’t run into fire with your sub-machine gun and die to a sentry) and take advantage of Sparks’s speed sparks can run from cover to cover with taking little damage. This is useful because if one of your teammates are injured and need healing but they are to far away to throw a health pack then you are going to need to run into fire more often then you would like to.
Health:
Sparks’s health is low but she does have health packs. You are going to want to keep at least 1 health pack for you because if you are hurt and give all your packs away and run into fire, you are going to be downed or killed.
Support:
Also you are going to want to stay a ways away from the objectives and keep your eye on your teammates. If your team is pushing to the objective, slowly push behind your teammates. Don’t go first because you never know what is going to be behind those walls! Stay away from any bullets flying because you don’t wanna get shot in the face while you are charging your Revivr.
That’s all folks!
If you have any questions you would like to be answered please post a comment on this post! 
~SiXtYnInE
