Stun is a very nasty condition and very out of line with the basic concepts of 4e.

Ritual Seed: Force
Prerequisites: Int 13, Ritual Caster, trained in Arcana, access to a power with the Force keyword
Benefit: You may spend a healing surge as a free action to gain the ability to create magical force effects for five minutes or until the end of the encounter. Some sample effects are as follows:

Force Enhancement (At-Will * Arcane): Free Action. You may use an Arcana check in place of a Athletics check, or an Intelligence check in place of a Strength check.

Force Aid (At-Will * Arcane): Standard Action. Choose a target within 5 squares and make a DC 15 Arcana check. If you succeed, choose one ally. That ally gets a +2 bonus to his or her next attack roll against the target, or to all defenses against against the target's next attack. This bonus ends if it is not used by the end of your next turn.

Force Push (At-Will * Arcane, Implement): Standard Action. Choose a target within 5 squares. Make an Intelligence attack vs. Fortitude. If you hit, you push the target 1 square.

Force Grab (At-Will * Arcane, Implement): Standard Action. Choose a target within 5 squares. Make an Intelligence attack vs. Reflex. If you hit, the target is immobilized until it escapes or you end the grab. You can sustain this effect as a minor action, and end it as a free action.
The target can attempt to escape on its turn. If it attempts to escape, the effect uses your Fortitude or Reflex defense. The effect also ends if the distance between you and the target exceeds 5 squares.

Force Move (At-Will * Arcane, Implement): Standard Action. Choose a target affected by your force grab. Make an Intelligence attack vs. Fortitude. If you hit, slide the target 3 squares. If the distance between you and the target exceeds 5 squares, your force grab effect ends.

Force Construct (At-Will * Arcane): Standard Action. Make a DC 15 Arcana check. If you succeed, you can create a force construct within 10 squares. The force construct lasts until the end of your next turn. In subsequent rounds, you may create additional force constructs, but the Arcana check DC increases by 2 for every force construct you have already created. You may sustain all the foce constructs you have created as a minor action, and dismiss a force construct as a free action. You may choose from the following force constructs. Your DM may also allow you to create additional types of force constructs, at his discretion.
Force Obstacle: You create a 1-square high obstacle that completely blocks a square. You cannot create a force obstacle in an occupied square.
Force Platform: You create a sturdy platform in one square. It negates difficult terrain and (at the DM's discretion) certain types of challenging and hindering terrain.
Force Ladder: You create a 1-square high ladder in one square. In subsequent rounds, you may increase the height of the ladder by 1 square by creating an additional force ladder on top of it.

Force Hand (At-Will * Arcane): Standard Action. Make a DC 15 Arcana check. If you succeed, you may use the mage hand wizard cantrip.

In addition, a player may be able to find creative ways to use force effects to earn successes in a skill challenge.

A player may also attempt more complicated effects with the force ritual seed. The DM may run these as skill challenges, and may allow the other characters to help contribute successes. For example, the DM may allow the PC to replicate the effects of the Tenser's Floating Disk ritual by spending a healing surge and succeeding at a Level 1, Complexity 1 skill challenge. If the challenge is failed, the healing surge is expended to no effect.