How to Use Ghostly
Ghostly even after the nerfs is one of the most powerful and flexible traits in the game. It's important to know what the trait does and how to use it properly.
Ghostly triggers after taking or dealing damage 6 times, sending 2 ghosts to the nearest enemies. These ghosts both heal your units and increase the amount of damage taken by the haunted enemies. The most important part of the trait is the extra damage. Your goal with this trait should be to collect as many ghosts onto a single unit as possible in order to achieve maximum damage output. This is where positioning is important, you want to stack your ghostly units and carries on an opponents weak side in order to quickly generate ghosts and kill the units to push them all onto one unit. Single target damage is also heavily valued in this comp for that reason.
When looking at itemization it's important to know that the most consistent way to generate ghosts on the units you want is by taking damage. This makes itemizing your tanks really important. Putting damage items on kayn and morgana is sub optiomal because it doesn't generate enough ghosts and morgana applies the trait to the backline which isn't optimal. Shiv is a great item to put on your team later into the game as ghostly does magic damage and shiv contributes towards creating more ghosts.
Senna Reroll Variation





















Senna reroll is the most popular variation of ghostly as senna provides a lot of single target damage for the comp as well as good traits and being able to reroll the other 2 cost tanks in the comp. For items you want last whisper on senna ideally for sunder and guinsoos for maximum damage output but it's not neccesary. The third item can be any AD item or offensive inkshadow tattoo. Redemption works really well in this comp as you can give all 3 of your ghostly tanks damage reduction, just make sure to put it in the middle of the units.
Kai'sa Variation

















The Kai'sa variation is really good if you have lots of tempo or are contested. The idea of this varation is the same as senna just with Kai'sa instead, playing senna until you find Kai'sa and swapping out jax for udyr if you find him. Kai'sa's ideal items are Infinity Edge, Last Whisper and Tattoo of Toxin. Last whisper is pretty neccesary but you can substitute the other items with basically any other AD or offensive tattoos.
Ashe Variation

















The Ashe Variation essentially plays like a weaker version of the Kai'sa variation but you swap out Kai'sa for Ashe and Jax for Amumu. This works really well because you can play Senna early and both Senna and Ashe want Guinsoos and Last Whisper.
Drayd Ghostly

























For the Dryad variation you reroll for Gnar and Kindred at 6 with the other ghostly units. Most likely you will be contested so going for just Gnar or Kindred is fine if you can quickly 3 star and get to level 8. You should look to play this from a spot if you get a lot of Gnar's or Kindred's and should try to play dryad early with strong boards to stack as much as possible. Gnar wants Bloodthirster and double Titan's Resolve, KIndred wants Blue BUff plus AP items. Ghostly spat is amazing on ornn because he'll be super tanky from stacking dryad all game and you can potentially go 9 for 6 ghostly.
Conclusion
Overall when playing ghostly your game plan might look like this: Play around Senna and 4 ghostly early, rolling at 6 on 3-2 to stabilize. If uncontested or you have a lot of the 2 costs then look to reroll, if not push level 8 and look for Kai'sa but take ashe if you find her and put in 6 ghostly.