To summ it up:
This is a different aproach on Malphite, there are several AP Malph builds out there but I feel they lack of defence. Our Malphite is tanky, has damage, very strong slow and ganking capabilities. The combination of the gaunlet, thornmail and boots build a great defence against AD, Reaver and hydra provide damage and the Mask has a nice magic resist, life and multiply our damage by 1,1.

Tactics allways should be defensive until level 6, then try to poke the enemy to 50% and combo. I often try to gank another lines and get back quickly with teleport.

Flash is a mandatory escape tool, must have, no question. Teleport will be used to return to your lane after ganks.

We will start with Dorans shield. Regen from this shield + your passive + second wind = hp sustain for the lane. This malphite will shine after reaching lvl 6, so it is important not to waste any exp fron the crips. Always ward the river and dont allow to gank you.

Only 2 options for mythical, Gaunlet or Aegis. Both of them proc your Grasp of the undying but the Gaunlet slows and stacks hp. Aegis on the other hand gives us the burning effect, more magic res and stacks ability haste. I prefere the Gaunlet.

90% of the times you will buy Plated Steelcaps. They scale with your passive and with your W. Sometimes when the enemy team has alot of AP damage and CC, go for Treads.

The core of the build is a mix of armor, health and damage. Thornmail is a must against autoattack champions, sustain and lifesteal. It gives a nice armor boost and health. Essence reaver is used because of the sheen effect and will be our main damage source. The crit chance is just a bonus, applies only on our autoattacks. At this point our W does cca 520 dmg. Hydra gives us more damage, more health which means even more damage. The cleave effect is great in teamfights and tower pushing.

At this point you will sell your Dorans shield and buy the last item. Abyssal mask will help you with your combo alot, Spirit visage will make you immortal providing magic resist, regen and multiplying your shield, Warmog will give you some damage from hydra and full regen in seconds.

The start is very hard for Malphite, Q is quite a manaburner. Try to focus on crips and poke only if the enemy champion is very aggresive. With level 6 a new game will begin. Try to poke the enemy to 50% hp and then combo: R - autoattack - W - autoattack - autoattack - autoattack - E - autoattack - Q

Grasp is great on Malph, it gives us damage, heal and hp every 4 seconds. Our mithic item will turn it on all the time. Shield bash gives us bonus dmg every time we gain a shield from our passive, second wind helps us sustain the lane and overgrowth gives us perma hp which also means some dmg from hydra.

Cheap shot provides true damage after our Q and R, ultimate hunter helps with the cooldown on our R.