Flash and Ignite, your two best friends.
Flash is kinda obvious, but use it in sync with Zhonya's to get out of sticky situations if the enemies have not died yet.
IF you can, try and Ignite then Flash into R if you really need to get out of there.
A sneaky tactic, use Flash or R to get into the enemy base and spawn camp. You should probably only do this if you are trolling or if they are REALLY under leveled/itemless because it's kinda dumb to do.

The runes here are pretty simple.
Since this is Blood Moon, it's essentially a massacre for kills so you would want to maximise your damage output right from the start.
You will be getting out 36.27AP which is better than a Fiendish Codex.
However, with this, you have sacrificed a lot of CDR which you may want to build by taking out, say boots, for another item with CDR such that you'd end up with Zhonya's and Lich Bane in the endgame. (Up to you)

The Ferocity masteries focus heavily on AP with masteries to help with CC and team fights like Expose Weakness. Bounty Hunter has been put up instead of the others as I'm sure you'd have it in you to be able to kill everyone on the opposing team with all that AP.
Deathfire Touch has been used to try and sap some of that health from the enemy in case you are unable to kill them.
The resolve path focuses on getting you armour and magic resist with a bit of health.
Explorer doesn't give much, but use it with your speed boost off Q to try and get to places quicker.

Fairly straightforward.
Max out Q as fast as you can as you would most likely be in team fights and Q will help a lot with the multitarget damaging.
Max W second as it will help with some burst damage.
E should be maxed last as it wouldn't prove too helpful in team fights but can be useful in 1v1 fights or to slow enemies down so you can run away.
Upgrade R whenever you get the chance to increase its damage output.

You would want to start with a Sapphire Crystal but an Amplifying Tome is just as good if you want more damage against the enemies. I would definitely suggest upgrading to Lost Chapter for more mana but if you are sure you are good with mana management (and since the gold gain is pretty quick) go for Fiendish Codex. This will be the base for the Morellos, your first core item.

Shoes would be a nice option next so you can get to your targets faster.
Sorcerer's Shoes are recommended to do more damage but if you feel like you are getting REKT, go for Ninja Tabi or Mercury's Treads.

Luden's Echo will be your third core item. If you are returning with a lot of gold, but the NLR for more damage, otherwise, go with the Amplifying Tome to upgrade into the Aether Wisp. The Luden's will give you some speed boost so you can get rid of the shoes in the late game if you wish.

Void Staff is your fourth core item and has a nice passive that ignores 35% of magic resist. That can completely ignore MRes from masteries and runes.
If enemies start bringing up MRes items, I suggest putting this on priority to maximise your damage output. As before, if you don't have the gold, go for the Tome but if you do, but the Wand.

Your final core item, the Rabbadon is your trump card to decimating the enemy team. Boasting 120AP and further increasing your AP by 35% is a great deal. You will only have two more slots open to buy prerequisite items so I suggest buying the NLR and the Wand but if you are low on gold, just get the two cheapest, or whatever you have available at the time.

Now, you have one more slot for items, but before you do that, if you want, you can replace the shoes for the Lich Bane for some AP, CDR, Mana and a bit of speed (I haven't tested which is better for speed but I'd say replace the shoes because you get more damage output out of this)

Your final slot should be used for Zhonya's which will give you some armour as well as CDR and a nice golden skin. The passive goes well with an Ignite into Flash and R to get out of the enemy's way (or at least I imagine it to work).

You can switch things around and buy things to your liking. I would suggest having Zhonya's there so you could replace the shoes into one of any of the other items in situational.