While Golurk has better attack and speed, Runerigus is an amazing suicide lead.
Runerigus has access to various utility moves, like will-o-wisp, destiny bond, haze and trick room. In addition, it also learns stealth rocks and toxic spikes. Its ability wondering spirit allows it to remove potentially dangerous abilities after being hit by a contact move. Its great bulk and access to two entry hazards (Toxic Spikes and Stealth Rock) is it's main attraction. It has a usable 95 attack stat, so it works well as a trick room attacker.
The main strategy is to lead with Runerigus, and set up your Stealth rocks and Toxic Spikes. You can also set up trick room if you need to. Your great bulk will usually allow you to set up both. You can use destiny bond if you're near death. If you're still healthy after the hazards, you can just spam earthquake.
Alternate moves include will-o-wisp, shadow claw, taunt, trick, memento and body press. This thing has an amazing movepool, so using it is a key to success.
If you want a physical ghost type, Dragapult is serperior in every way to both Runerigus and Golurk. Other good physical ghosts include Mimikyu and Aegislash.