How do I assemble this Perception-based Defensive power into Mutants and Masterminds?

Question

My Tabletop group has been discussing running a game of Mutants and Masterminds in the future, so I thought I should get a head start and attempt to build a character. The character i have in mind is a fairly Strong, Fast and Tough guy with a selective High-Cognition vision. The way that I had imagined this working is that whenever someone makes an attack at my character that they're aware of, they can take a reaction to increase their visual perception range to -1/1000ft, increase their processing time by x1000, gain analytical levels of sight and be able to accurately judge distances for however long they wish. Using the information they gather from this, my character would gain advantage on avoiding attacks from the attacker(s) depending on how well I rolled and/or how many ranks they have. The drawbacks for this are fairly steep; firstly, they would lose all other senses until their next turn (where the power would wear off). Secondly, and this is the most important one, the character would get tunnel vision regarding the attackers, something as small as the guy immediately in front of them in melee range and a maximum of 5 guys relatively close together at long range. As a result, his Parry and Dodge potentially skyrocket versus a select few opponents, but absolutely diminish versus opponents outside their limited field of vision.

I've been referencing the Powers section in the d20 hero SRD, and the things I found in there sort of fit the ideas that I've been working with. While there are the Analytical, Danger Sense, Increased Range and Fast Reaction additions to senses AND I could squeeze my tunnel vision idea under Limited and Unreliable, all of these modifiers are permanent and not reactionary. Moreover, the Deflect power is the closest thing I could find to the defensive buff I was looking for, but it only counts as a substitute for Parry and Dodge, not an additive.

So here is what I am SPECIFICALLY asking people familiar with this system:

Can I make my concept happen through Powers exclusively?

Can I make my concept happen through mixing Powers and Advantages?

and

Is my concept impossible in this ruleset?

Answer 1

Short answer, no, this is not how the system works

Mutants and Masterminds holds PL as a fundamental concept. Amongst its aspects, you cannot transcend PL in ways other than temporary. A more minor issue is that it sounds like you're trying to read a little more into the names of the powers and their modifiers than in what they do. A central theme of power-building in M&M is that the powers do exactly what they state in their entry, no more and no less. Subtleties that distinguish one power from another are in the Descriptors, which provide more fuzzy benefits and drawbacks worked out between you and the GM.

Longer answer, this power is completely doable as long as you don't mind your "peak" performance being limited to the people you're focusing on

Your campaign will have a target PL. You cannot exceed that PL outside of temporary measures such as combat maneuvers (Power Attack, All-Out-Attack, etc) and circumstance bonuses (miss chance from invisibility, Favored Opponents, etc). Also, the game assumes that people are hitting their "caps" by having at least one attack at PL, and that your defenses are at least mostly there (often characters will have a bit lower Dodge or Parry). One way to work this is to build your character at PL and then apply Quirk (Power Loss) or Flaw (Limited) to their defenses to model only being that good against the opponent you're focused on. The rule of thumb for Limited is that it should apply at least half the time, with Quirks for rarer cases, point value agreed upon between you and your GM. Alternately, talk to your GM about Complications, which apply a softer model where sometimes your GM will apply it, reducing your defenses, but you get a Hero Point for it.

If you still want his senses to become that much more when under attack, you can do the same trick there, building them at full power, then applying the Flaw, Quirk, or Complication that they're only available at that level when under attack. Although, it sounds like that was more flavor for him gaining additional defenses in combat rather than him actually gaining better ability to perceive things.

For the "split-second reaction", I would also suggest Danger Sense and Uncanny Dodge so that you don't get flat-footed by, say, the invisible assassin or a sniper shot.

Rule 0 answer

Lastly, if your GM is up for it, PL doesn't have to be so rigid, and they could allow you to trade off your defense for a small number of targets at the cost of being easier to hit by others. That's between you and them, although in my experience, much like with Monopoly, it's easy to break the game by ignoring the rules, often in subtle ways that are hard to realize.

Answer 2

Yes, you can do this, but you probably shouldn't.

Mutants and Masterminds works based on a system where your attacks and defenses are limited by your Power Level, and buying them up to those limits is fairly cheap. As a result of this, every character should buy all of their defenses up to their Power Level limits, and that's what the game is balanced around. Due to these facts, any power that buffs your combat abilities should be able to be "always on", otherwise you're going to have two states: at the balanced levels when your buff is active, and a weakened state when your buff is inactive.

So, you could create a power that looks something like this:

Senses 2 (Analytical Extended 2 Visual Sense, Limited to Enemies Who Attack Him) Linked To Reaction Quickness 8 (Limited to Mental Tasks) Linked To Enhanced Defenses (Dodge, Parry) X (Limited to attackers marked with Analytical Vision) (6 points + 1 point per level of Dodge and Parry granted)

This would let you buy up your Dodge and Parry for half price, at the cost of becoming horribly vulnerable to anyone who you haven't marked with your vision.