Q 233:
A233 What you have here is a whole stack of effects that say "subject takes half damage, willing ally/enemy/caster takes the damage not taken by the subject." So if an attack hits your psion, everybody (the enemy, the psicrystal, the paladin, and the psion himself) takes half the damage that would've been dealt by the attack. That is, if the attack dealt 10 damage, each and everyone person involved takes 5 damage.
Empathic Feedback deals "damage equal to the amount it dealt to you." So the attack -also- takes half the attack would've dealt. You might expect them to take full damage, but the shielding effects say, "the subject takes only half damage from all wounds and attacks," etc. So the psion (using empathic feedback) is only taking half the damage the attack would normally deal.