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.
Basicaly the main gaol of the runes is to counter the 25 armor pen on most bruisers and carries. Why did I die in lvl 3 .... well thats cause the enemy stacked armor pen....
We need to counter this asap to avoid dying in early game.
Next after we counter the runes of the enemy we still have marks and we still have glyphs.
Glyphs : Take MR per level runes
Marks: hmmm.... tough choice... the bes for the long term is magic pen.
If guide is popular. Ill edit and make more comments. if not Im leave it alone.