I think you can probably do a multi-target block with Incite Emotion as written, even without upgrades.
Multi-target attacks are another matter. Several people have written homebrew upgrades allowing them.
If you'd like to use such an upgrade, I suggest you grab the one from Incite Effect.
INCITE EFFECT [-1]
Description: You can do a thing. A special thing, that cannot be done by most people. Maybe you can control clouds of smoke, maybe you can inflict fear by shouting. Or maybe you can summon the aid of two thousand invisible squirrels. Whatever.
Skills Affected: Any.
Effects:
Incite Effect. Pick a type of effect and a skill that's related to that type of effect. You can use that skill plus two to perform maneuvers and blocks related to that type of effect against anything you can touch. At the GM's discretion, this may also enable Declarations.
At Range [-1]. You may use Incite Effect on anything within your line of sight.
Incite Limited Effect [+1]. (Requires At Range) Do not add two to your skill when using Incite Effect. This upgrade is not compatible with Incite Physical Effect or Incite Mental Effect.
Incite Physical Effect [-1]. You may use Incite Effect to perform attacks that inflict physical stress. These attacks have a weapon rating of 2. They use the same skill as your maneuvers and blocks, but without the +2 bonus. If you have the At Range upgrade, then targets must use their Endurance to defend against these attacks. If you do not have the At Range upgrade, then targets may use whatever skill they would use against ordinary Fists attacks instead.
Incite Avoidable Physical Effect [-0]. (Requires Incite Physical Effect At Range) The targets of your Incite Physical Effect attacks defend with Athletics.
Incite Mental Effect [-1]. You may use Incite Effect to perform attacks that inflict mental stress. These attacks have a weapon rating of 2. They use the same skill as your maneuvers and blocks, but without the +2 bonus. If you have the At Range upgrade, then targets must use their Discipline to defend against these attacks. If you do not have the At Range upgrade, then targets may use whatever skill they would use against ordinary Fists attacks instead. This upgrade does not allow mind control; characters taken out with it are generally overwhelmed with emotion or driven insane.
Incite Potent Effect [-1]. (Requires Incite Physical Effect or Incite Mental Effect) Attacks that you make with Incite Effect are weapon 4.
Incite Protective Effect [-1]. You may use your the skill that you use for Incite Effect to defend against physical attacks.
Incite Restrictive Effect [-1]. (Requires Incite Physical Effect or Incite Mental Effect) You may use Incite Effect to grapple targets within the range of this Power, using the skill that you use for Incite Effect. Grappling with a physical effect inflicts physical stress, while grappling with a mental effect inflicts mental stress.
Incite Mass Effect [-1]. (Requires Incite Physical Effect or Incite Mental Effect) You may make spray attacks and zone-wide attacks with Incite Effect. If you attack your own zone, then you are affected normally by the attack. Even if you lack the At Range upgrade, targets defend against your zone attacks as though you had it. This upgrade does not affect your ability to maneuver, and no penalty is incurred when attacking a zone with it.
Incite Explosive Effect [+1]. (Requires Incite Mass Effect) You may not make non-zone-wide attacks with Incite Effect.
Incite Selective Effect [-1]. (Requires Incite Mass Effect) You do not harm yourself when attacking your own zone.
Incite Persistent Effect [-1]. (Requires Incite Mass Effect) When attacking a zone with Incite Effect, you may take an accuracy penalty (before rolling) in order to extend the duration of the attack. For each point of accuracy sacrificed this way, the attack is reapplied at the beginning of another exchange. You may take actions to extend this effect as though you were an evoker extending an evocation.
Incite Additional Effect [-1]. You may select another effect to create with this Power. You may also select another skill to use that effect with. If the other upgrades that you have are appropriate for the new effect, you may use them with it. You may also upgrade the new effect separately.