Having played through Aspenwood just about all day, I've thought of a few elite skills that I think would be both enjoyable to use and fairly (as far as I can see) balanced.
en = energy
ct = casting time
rc = recharge
Please note that all skills are elite.
Assassin
Silencing Twist (Dagger Mastery)
en-10
rc-15
Duel Attack. Must Follow an Off-hand Attack. If this attack hits, you strike for +5-18 damage and your target may not cast spells for 1..3(4) seconds.
Night's Cloak (Shadow Arts)
en-10
rc-45
Stance. You lose all enchantments. For 2-7 seconds, you cannot be seen by radar, and cannot be targeted. You leave a black trail while under the effect of Night's Cloak and you lose this stance if you attack or use a skill.
Coward's Demise (Dagger Mastery)
en-5
rc-8
Lead Attack. If this attack hits, you strike for +7-24 damage. If you strike a moving foe, that foe is crippled and poisoned for 6-18 seconds.
Elementalist
Brittle Barrier (Earth Magic)
en-15
ct-1/4
rc-7
Enchantment Spell. For 10 seconds, the next attack against you is blocked, and if your attacker was adjacent, they suffer 15-70 damage and suffer from weakness for 5-16 seconds.
Glacier Bindings (Water Magic)
en-25
ct-2
rc-20
Hex Spell. Target enemy's movement speed is slown by 33-10% per second for 3-10 seconds. When this hex ends, that enemy takes 20-85 cold damage.
Frostbite Armor (Water Magic)
en-10
ct-1
rc-45
Enchantment Spell. For 12-35 seconds, all attacks against you slow your attacker's movement speed by 33% and attack speed by 25%.
Several Elite Skill Ideas
Glitched
MithranArkanere
Gregslot
I liked Cowards Demise, Glacier Bindings and Forstbite Armor