Generic Powers: Make Your Hero Versatile!
Building a unique and useful hero doesn't have to be just about being the absolute best at healing, neutralizing enemies, or dealing damage. Sometimes, the coolest moments during battle are when a Tanker, Blaster, or Scrapper pulls out a little green tricorder and heals his or her teammate using Aid Other, or when a Defender or Controller gets surrounded by enemies and suddenly pulls off an Air Superiority attack that stuns the target.
During gameplay, especially after I built my Defender, I realized that I wanted all my heroines, not just one, to have similar kinds of support powers, because I like to be helpful to my team as well as being good at dealing damage/healing/neutralizing enemies. But generic power pools are not only good for support powers--they are the only ways to get faster traveling powers, as well as neat powers that supplement power sets.
Below are explanations of each generic power pool, as well as examples of how you can benefit from taking that power pool. In each listing, you can take the first power listed at level 6, the second at level 8, 10, or 12, the third at level 14, and the fourth at level 20. You must take one of the first two powers in order to get access to the third power on the list, and you must take two powers from the power pool in order to get access to the fourth power on the list.
IMPORTANT NOTE:: Each hero can only take powers from 4 of the available power pools, as I found out from unfortunate experience. I wanted to take Recall Friend (from the Teleportation pool) with my Scrapper, Catarinya. Problem? She already had powers from Fitness, Concealment, Leaping, and Medicine. Thus, I could not take Recall Friend unless I respec'ed her and changed what power pools I took with her. Choose your Generic Power Pools wisely!
Read more about the Pool Powers in the ParagonWiki article.
Concealment
Great For: Heroes who want to be able to "stealth" through levels or surprise the boss of an enemy group without setting off the whole roomful of bad guys. Also good for hiding and Resting after getting beaten up pretty good. This power pool is not often needed by most heroes, but is good for certain builds, such as a Blaster who has some damaging up-close powers but doesn't want to get defeated before they can go off effectively.
Most Useful Powers: Stealth, to hide in the middle of fighting and give a defense boost. Invisibility and Phase Shift are good for those moments when you just CANNOT afford to be seen, but they aren't any good in combat--Invisibility makes you unable to attack, and Phase Shift goes away after 30 seconds. Grant Invisibility is great for people who enjoy buffing their teammates; it basically gives them Stealth for 2 minutes.
Flight
Great For: Anybody who wants to fly!
Most Useful Powers: Fly is great for long distances over difficult terrain, and is THE most desired of the four powers. You cannot get Fly until you have taken either Hover or Air Superiority, however. Hover is good for being in combat while still being in the air, but it's not for flying long distances. Air Superiority is a strong close-combat attack, great if you don't have any other close-combat attacks or if you need one to supplement your current lineup. Group Fly, while not the most desirable of the four powers, does have its uses in letting one member of a team carry those who cannot fly. (Group Fly is tricky to control--you can accidentally "leave" a teammate behind if you travel too fast!)
Fighting
Great For: Heroes who want to add a little more close-combat punch to their repertoire. As well as being a more obvious choice for Tanks and Scrappers, this can be a great little addition for Blasters, Defenders, and even Controllers who need a little bit more defense when enemies surround them. This pool isn't quite so useful as others, but does have specific instances where it can serve as a second set of attacks, along the same lines as Brawl and your ranged Origin-based attack you get when you first create your hero.
Most Useful Powers: Tough and Weave, for adding to Defense and resisting Immobilize attacks. You have to take the Boxing and/or Kick powers to have access to either of these powers, but it is a small sacrifice to make if you really want the added defensive ability. Weigh your options carefully--you might have something in your defensive power pool which works as good as or better than Tough and Weave.
Fitness
Great For: Just about any hero! Swift and Hurdle are useful for heroes who need their speed and jumping abilities maxed out, while Controllers and Defenders especially will love Health and Stamina for pumping up max health and Endurance. (Health and Stamina stack with always-on powers such as Fast Healing and Quick Recovery, so these two powers are HILARIOUS when used by a Willpower Tank or Scrapper...they almost never die or run out of endurance!)
IMPORTANT NOTE: As of Issue 19, every hero will get Fitness built in as an inherent power tree! (I guess the developers figured since everyone takes it anyway, why not make it an inherent tree?) If you have a hero that took powers off the Fitness tree before Issue 19, you'll need to respec them so that they can have access to the Inherent Fitness tree (and therefore, you won't have to waste 4 power picks on the Fitness tree).
Leadership
Great For: Heroes who work in teams a lot and focus on bolstering their allies instead of taking a lot of shots themselves.
Most Useful Powers: Maneuvers boosts your Defense as well as that of your allies, while Assault does the same for Attack. Tactics boosts your Accuracy and your allies' Accuracy. These three auras work pretty well. Vengeance can be hard to pull off, because it requires one of your teammates to die before it can go off. Remember: you have to be pretty close to your teammates to boost them, so play it carefully, especially if your hero has a relatively low Defense and doesn't need to be too close to the battle.
Leaping
Great For: Heroes who want to jump around everywhere instead of flying.
Most Useful Powers: Combat Jumping and Super Jump, for sheer traveling distance and upped defense. You can't run the two together, but it's good to have both--Combat Jumping for bouncing around the enemy like Spiderman, and Super Jump for getting across hero zones. Acrobatics is good for giving you extra protection against being knocked back, and Jump Kick is a good attack if you need another, but it isn't completely necessary.
Medicine
Great For: Anybody who wishes they had the Empathy power set but can't get it.
Most Useful Powers: Aid Other and Aid Self. Stimulate is not worth the power slot, basically--I've never seen that it really does quite as well as Clear Mind. Resuscitate is a stripped-down Resurrect, leaving its target completely healed, but with no endurance; it's a great stand-in when your healer is dead and doesn't have an Awaken! Remember that these powers, unlike the Empathy power set, can be interrupted, so don't try to use Medicine powers while being attacked, while running, or while jumping/flying--they won't work unless you're standing still and activating no other powers.
Presence
Great For: Any hero who needs a little intimidation power.
Most Useful Powers: Intimidate and Invoke Panic, for the ability to scare the pants off either a single foe or a group. Don't discount the power of spreading fear Challenge and Provoke are good if you don't have a Scrapper's Confront power or a Tanker's Taunt power, but they do need an Accuracy check first, which means they can miss.
Speed
Great For: Heroes who have a need for speed, either in attack or in traveling
Most Useful Powers: Hasten and Super Speed. Hasten helps your powers recharge faster for a short time, which is great news for healers and fighters alike! Super Speed is a supercharged Sprint, cranking up your running speed to nearly 80 mph, and it also gives you a tiny Stealth bonus, making enemies less likely to see you. Whirlwind is a good Knockback attack, great if you need another attack, but not necessary for all heroes; Flurry is a funny close-combat attack similar to Sands of Mu (fast series of punches).
Teleportation
Great For: Heroes who generally want to help their teammates and themselves get places faster.
Most Useful Powers: Recall Friend, by far...it can bring a teammate across a zone in no time. Teleport Foe gets an enemy close to you so that you can get it away from a teammate who's getting beaten down, and Teleport itself puts you in an area within your range (not absolutely ANYWHERE, unfortunately). Team Teleport sounds good in theory, but actually assembling a team together for such a feat would be difficult, and like Teleport, you can only go so far with it.