Empowered ISOs in the Facebook game Marvel: Avengers Alliance add a special ability to the attached character. There are three separate types of E-ISOs: character restricted, class restricted, and unrestricted. The latter type can only be purchased in the store and only for command points. Since empowered ISOs can be swapped between characters at will, they tend to be a solid investment, if you have the spare command points. The following guide to unrestricted empowered ISOs in Marvel: Avengers Alliance will help you determine which are best for your team and whether they are worth the cost.
Sympathetic E-ISO, 10 CP – When this character uses a buff power, the character heals some health. This is a particularly powerful ability for Rescue, who tends to use one to two buff powers per turn. It is also broken for heroes like Omega Sentinel who change classes, because that change is tagged as a buff power and you can use it an infinite number of times per turn. The latter is an exploit and will likely be fixed in the future.
Distant E-ISO, 40 CP – All ranged attacks on the character gain an improved chance to score a critical hit. This is only meaningful for characters that primarily have ranged attacks, and even then isn’t a great deal. For 40 CP you can almost afford most alternate costumes, which tend to give a better boost than this will.
Resonant E-ISO, 10 CP – This is a steal on any hero that has all magic powers, like Magik, Scarlet Witch, or Dr. Strange. Whenever the hero uses a magic power, the hero heals a little. A very good buy, especially if you use a lot of magic heroes regularly.
Recovering E-ISO, 20 CP – You get one for free, so there is almost no reason to buy this. While equipped, the hero regains some health when the hero recharges. The ability is nice and is especially good for heroic battles, many of which require heroes to recharge at least once during the battle.
Sheltered E-ISO, 20 CP – This is almost identical to Recovering, but the hero gains a shield when recharging, rather than health. A shield is usually slightly sub-optimal, but can be a better option on heroes who have attacks with the Finest Hour ability. If you are considering a second Recovering, this is probably a better choice.
Close E-ISO, 40 CP – Close is the melee version of Distant and equally unimpressive. Save your command points and just buy an alternate costume instead.
Surprising E-ISO, 10 CP – Surprising is a very popular empowered ISO, for a very good reason. All attacks from this hero have a small chance to stun. The chance is low, but stun is so powerful and 10 command points are so cheap, that it is usually worth buying three of these.
Relentless E-ISO, 80 CP – Relentless is more expensive than any alternate costume in the game, with the exception of the Archangel uniform. The reason it is so expensive is that it makes the hero immune to stun. This is a game changer on par with most alternate uniforms. You may seriously want to consider this, despite the high cost, if you regularly engage in PvP or simply have a hero that is critical to the synergy of your team.