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.
This is the Morg that I have been playing in the majority of my ranked matches. She starts off being very hard to kill and can easily solo a lane. In 5v5 especially, teleport is perfect for her to maintain lane control. The cooldown on teleport seems to coincide with her making enough cash for each item.
The runes I have chosen are meant to keep her mana and health up throughout the progression of the game. The magic pen and cooldown reduction serve to make her a dangerous offensive character as well as an effective support.
You may look at the masteries and wonder, but with the philo stone, dorans ring to start, and mana per level runes, you maintain enough mana for your teleport to refresh so you can go get more. Also, your team will probably be willing to give you blue since you're such a key support role.
These can certainly be tweaked based on your playing style. If you plan on being in lane with a partner, clarity is a viable substitution for teleport. I usually like to use ignite in games because it is an excellent way to keep the Warwicks and Mundos of the game in check. It might also get you some kills so you can fund that Deathcap as quickly as possible. Sometimes I choose exhaust so I can single out targets for my ulti and keep them in range of the second phase.
Pros / Cons
[*] Incredible survivability
[*] Good damage output later in the game
[*] Your team will love the support
[*] Unbeatable lane control
[*] Low damage output to start
[*] Low mana early on
[*] NOT a tower killer
[*] Don't expect a ton of kills