Techies + Io

Why this works

Dropping onto an unsuspecting enemy with Relocate gives Techies a perfect setup. He can land a Sticky Bomb immediately, and Io's Tether helps him stay on top of the target to ensure it detonates. If Techies needs to commit with Blast Off! for the silence and finish, the healing and damage reduction from Io can be enough to let him survive what would otherwise be a trade. It creates a mobile ganking threat out of a hero that often prefers to play defensively around his own established positions.

This plan depends entirely on a long cooldown, though. Using Relocate for one kill means it isn't available for saving an ally or taking an objective elsewhere. Later on, Io often gets more value by empowering a traditional right-clicking core in teamfights, leaving Techies to set up traps on his own. The enemy team can also anticipate the gank by playing safer when they see Io is missing. It's a useful tool, but one that requires both heroes to commit completely, which isn't always the best play.