Clockwerk

Tips

 * Scepter buff is actually extremely useful for him.
 * Rattletrap has 2 escape mechanisms, use them to enter fights, as well as getting away from them
 * Battery Assault works as a ministun so it's great for interrupting channeled spells or tps.
 * You get great map control with Rattletrap
 * You can also abuse the global cast range of Rocket Flare to kill fleeing opponents.
 * Rattletrap is a mortal threat to many heroes. But he gets weaker late game without items. So farm.