I'm sorry I meant Cull of the Beast, not herd, my mistake

Thank you for the clearification on this though..
Cull of the Beast doesn't exist.
Nor does that phrase make much sense.
Do you mean 'Call of the Beast'?
Alright. Let's teach you how to read a power then.
At - Will * Charm, Implement, Primal, Psychic
This line is the usage and keyword line. There is sometimes some rules baggage contained in keywords, in this case 'Implement.' It allows you to use the enhancement bonus of an Implement with this power.
Standard Action Area burst 1 within 10 squares
This line tells you which action it costs to use it, and the
attack type and [/i]range[/i] of the power.
The attack type is Area---that means that the origin square of the power is at a distance to you, you must have Line of Effect to that origin point, and that it provokes attacks of opportunity.
Next is the range--"burst 1 within 10 squares." That means that the power's area includes all squares within 1 square of the origin, and that the point of origin must be within 10 squares of the user.
Target: Each enemy in burst
This line tells you what the power targets. In this specific case, it only targets enemies in the burst mentioned in the range. Some powers target creatures, some only allies, and yes, you even have some bursts (generally these are Close powers) that only have a single target in the burst.
Attack: Wisdom vs. Will
For every attack power, you make a seperate attack roll against each target. Unless the power says so, you can always hit some, miss others.
Hit: The target can't gain combat advantage until the end of your next turn. In addition, on its next turn, the target takes psychic damage equal to 5 + your Wisdom modifier when it makes any attack that doesn't include your ally nearest to it as a target.
This power is one of the few non-damaging (in the immediate sense) attacks in the game... instead it assigns a stipulation for damage. A basic minor debuff to foes that force them to attack nearby allies. Because no damage is rolled, most bonuses to damage do not work with it, as they generally add to damage rolls, or are 'additional damage'
However, if you -did- roll damage for this power (see Chill Wind), then you check. If it is a Melee, or Ranged power, you roll damage separately for each target. So, two targets hit mean you roll damage twice, once each. If it is a Close or Area power, then you roll damage once, and apply it to all the targets. (Exception: Critical hits always maximize damage for that one target)
Level 21: 10 + Wisdom modifier psychic damage
This is a modifier line, and it changes the power based on that modifier (in this case, being level 21.)