Venomort - Lv.120
A single Viper pet is capable of killing any unit in the game without breaking a sweat. You're permanently invisible, you have a dozen Vipers, and they all fly through walls.
TO MICRO THE VIPERS LIKE A PRO: in the Dota 2 options menu, go to Hotkeys -> Advanced Options. Bind the movement command "Select All Other Units" to V. When directing your Viper swarm, quickly press V -> A -> LeftClick to make them attack everything they see when moving toward that destination. Then press F1 to return focus to Venomort. You can double-tap F1 to center the camera on Venomort.
Signus Charm greatly increases the cooldown of E, but its gem effects also reduce Q's cooldown to nothing, and cause E's current cooldown to be reduced when casting Q, resulting in permanent E invisibility uptime. Meanwhile, your Enchanted Solar Cape works alongside Iron Treads of Destruction and Spellfire Gloves to practically remove the cooldown of R, allowing you to print swarms of deadly Vipers that phase through walls, have tens of thousands of HP, attack 10 times per second, have a gigantic splash damage radius, and deal all three damage types to ensure that no immunities can repel them. Even with mediocre Ordinary-tier gems, you can expect each individual pet to output 40m damage.
Observe that, uniquely among RPC builds, this particular Venomort needs no attribute rolls on gear, preferring instead to pick up Base Ability Damage% in most slots and Armor Pierce on his gloves. This is because Venomort himself is invisible, safe and happy far away from the combat zone, while his cloud of Vipers disintegrate enemies; the Armor Pierce they gain from Venomort is heavily boosted by R2, allowing their Physical damage instances to more quickly punch through Spell Immune targets, which will not be affected by R1 at all.