Hello my name is BurstSpirit and here is my guide about Malphite.
But not the casual tanky version but a bursty Mid-Lane-Nuker.
I am currently in Platinum on Euw and Malphite is my main champion.
I hope you enjoy it!

I choose scaling CDR Glyphs because your Ultimate Unstoppable Force is the key to killing people and the Cooldown is really long.
Everything else is pretty standard in this runepage.

After Patch 5.13 I still think Morellonomicon into Luden's Tempest is the best choice when your main goal is to oneshot squishies. After Luden's Tempest you can go Rabadon's Deathcap or Void Staff depending on the Magic Resistance of the enemies.
Afterwards you can build whatever fits the situation.

Like I already mentioned in the item notes your early game is not that fun in most games.
Since you are melee range and your mana cost on Seismic Shard is quite high you will have problems with csing early on. After a few levels when your damage on Seismic Shard gets a bit higher you can poke and zone the enemy and get your cs.
As soon as you are level 6 you can try and kill your enemy when he is low enough from your poke. Try to not use ur Unstoppable Force from the maximum distance so you don't give your opponent too much time to react and maybe flash your combo.
If you don't get rekt too hard on the early levels your first back should be around 1k gold so you can get a Fiendish Codex a few pots and a Vision Ward.
Afterwards your laning phase will get a lot better and you can trade really well especially when you get Blue Buff. If you have the oppertunity to roam go for it. A good ult on bot lane usually results in a double kill.

After Laning Phase you can either try to go solo and find somebody to oneshot or group and look for a good Unstoppable Force in a Teamfight. With the Movement Speed from Luden's Tempest and Fleet of Foot it is really easy to get a pick onto somebody. But always try to bait the Flash first so you do not waste your Ultimate. In Teamfights you should think about what your priorities are. Oneshotting the enemy Vayne who is a little bit out of position or landing a 4 man Unstoppable Force on the remaining members who might be tanky. Making a decisions like the one in the example depends on many factors. You should generally know your damage output and the enemy's items. If the Vayne has a Banshee's Veil you will not be able to kill her instantly and be in the middle of nowhere with no cooldowns. At that point you pretty much wasted your Unstoppable Force and maybe even your Ignite or Flash. Just always ask yourself a few key questions:
What is my goal ?
How high is the chance of achieving that goal without problems?
Will it be worth it?

Pros:
+Fun
+Burst Damage over 9000
+Pick Potential
+Nice slow on Seismic Shard (really annoying in lane)
+Naturally good against AD
+ Unstoppable Force on 3 or more enemies is GG



Cons:
-Low Mobility
-Somewhat relying on Unstoppable Force
-Weak Laning/Waveclear
- Banshee's Veil is a hard counter

I really hope you enjoyed this guide. If u have any questions you can ask me here or add me directly in LoL. Anyway good luck and fun playing AP Malphite and see you on the Rift

Greetings BurstSpirit

Malphite