Precognition power (PL7)

[Grek]

There's several Advantages which are suitable for precogs. Uncanny Dodge (not vulnerable during surprise rounds) and Danger Sense (can sometimes act during surprise rounds) are both obvious picks. But also Improved Initiative or Seize Initiative, for that 'sees things coming and reacts quickly' flavour. Assessment is also a good way to represent a precog who gets more information than just the obvious about dangers, for example knowing that a particular person is actually a lot faster/tougher/stronger than they look.

I would not suggest using Deflect. It requires a standard action every turn, after all. Much better to use some level of Impervious on your defenses. Taking Dodge/Parry together is always a good idea. Another angle you might consider if you want to be through is Immunity: Interaction Skills, which makes it so that your character can't be bluffed/seduced/intimidated/feinted, since they can see the trick coming and know that it's just a ruse. The feint resistance is particularly important for Dodge/Parry based defenses, as it can cut right through them. You might also consider Second Chance: Immobilization, since that's another big vulnerability.

Precognition and Reaction are both 'ask your GM' powers, so you are right to hesitate to combine them. How about Concentration Remote Sensing as an alternative? Much more definite on what triggers it and what information you get, plus no GM advice saying to make the information 'obscure and cryptic', plus the option to spend actions to get more information by continuing to observe the threat. Same cost, too.

One more fun thing to do as a precog: Variable Equipment Limited to Protective Gear. Just like how Batman always seems to have the perfect tool for the job because he's Batman and planned ahead, you have the perfect tool for the job because your danger-sense got a lot quieter when you put the shark repellant in your toolbelt.