Dragon Knight + Shadow Shaman

Why this works

Taking objectives together is the main idea here. A Dragon Knight in Elder Dragon Form can tank tower damage while hitting the building, allowing a Shadow Shaman to drop Mass Serpent Ward and melt it. This dual threat forces the enemy team to react and can open up the map. For ganks, the lockdown potential is also potent. Dragon Tail provides an instant stun, which gives Shadow Shaman a clean setup for a full-duration Shackles. This can be enough to secure a kill on a key target and begin a push.

The whole strategy is very committed and predictable, however. Once Dragon Knight uses his ultimate and Shadow Shaman places his wards, they have invested their biggest cooldowns. A smart opponent will simply disengage or use strong area-of-effect spells to turn the fight. Both heroes can also struggle if they fall behind, as they lack the mobility or farming speed to recover easily. If they can't establish an early tempo, their mid-game push timing never really comes online, and they can't effectively pressure the map.