Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
With Malphite i like to use his E ability as my advantage and stacking Armor. I start out with mostly Armor and HP Runes, I always get Q ability first and max that out first. Q&E and the first to get maxed.
For Items i like to have alot of HP if trying to gank at beginning of match so i get Red Ruby Crystal, If you like to harass and use your Q skill alot to keep the Enemy away trying to make it so they get experience, Doran's Ring can be a good first item pickup too. After i get Ruby Crystal or Doran's Ring i always go for Armor boots next. with potions if needed. After armor boots i like to get heart of gold, which i turn into Randuin's Omen eventually. After Rand's i go for Frozen heart and i wait to get the glacial shroud so your cooldowns are reduced more. My build is normally different in everygame but i tend to get the same items just different sequence, I dont really worry about magic resist cause if you can get your full build with around 470 armor then anyone on the otherteam that is AP and not AD you can boom on and they will usually die very quickly. and if your playing against a AD then your E ability plus frozen heart reduces their attack speed & you have so much armor with thornmail & GA. etc... Ghost and Ignite or Exhaust & Ignite are the Summoner skills i use.