so i want to use starro, but i am not sure on how the multi-attack works. can he attack twice per turn? when does he pull his markers, since he is quintesseance, can he attack twice in round one, twice in round three, and then pull? or did i read the instructions wrong and he can attack with two tokens?

Not a lot of time to explain but basically.... you give the character a power action to use multi attack... then multi attack gives you the option to make two ranged combat actions, close combat actions, or power actions as free actions. So basically you could give starro a power action to use the multi-attack, and then you could declare psychic blast, or running shot, or close combat expert... or basically any combat action really. For the second attack, you subtract one from your damage value. It's kind of like flurry... but instead of getting two close combat attacks as free actions... it gives you your choice of close combat, ranged combat, or power actions.

You subtract one from your damage value for all attacks made using multi-attack, not just the second one (that's the rule for the duo attack ability).

In addition to what was already said:

from the Starro rules:
"Actions
Starro can be given only one action during its controller’s turn. Starro can be pushed even when it has two action tokens; it does not take pushing damage. If you assign an action to Starro when it already has two action tokens, do not mark it with another action token."

He can take one action per turn, even if he already has two tokens.

Note that this is due to errata.

The rulebook states that you reduce the damage DEALT (which would mean that each target has its damage reduced), but the errata changes that to the VALUE (meaning that you reduce it before dividing it up).

So, could I declare Multi-Attack and Psychic Blast twice? or Phasing/Teleport then attack? I just got Sinestro Corps Anti-Monitor and want to be 100% sure on things.

Yes and no, respectively.

MULTIATTACK Give this character a power action. It can use two free actions. These free actions can be power actions that include an attack, close combat actions, or ranged combat actions, though free actions gained from this power can’t be used to activate this power. Resolve the first free action before giving it the second. Modify this character’s damage value by -1 to a minimum of 1. This character can’t use feats when using this power. This ability can’t be countered.

Phasing/Teleport is not a power action that includes an attack. This power is called MultiATTACK for a reason

But I can Psychic Blast twice, correct?

That is what I said

Sorry I left my Rosetta stone in my other wallet . Thanks for clearing that up.