Illusion
Illusion is a combat skill. The Mesmer's clones and confusion.
Like every skill it climbs to level 99. XP Boosts (+30%) and the Captain's Subscription (+20%) stack, for +50% XP while both are running.
Abilities

Shield of 12% health.
15 mana · 18 s
80% damage to up to 4 enemies around the target (5 m), slows.
15 mana · 15 s · 5 m area
Every clone rushes the enemy and bursts, one a second.
15 mana · 15 s
Elite: for 20 s you look exactly like your clones; half of all blows at you miss, and you can swap places with a clone.
30 mana · 90 s
During Confusion: swap places with your first clone.
6 s
260% damage, weakens, +1 clone.
20 mana · 12 s
140% damage to up to 4 enemies around the target (4 m), weakens.
15 mana · 12 s · 4 m area
Conjure 2 clones (3 at most). Each clone strikes alongside you for a third of your damage.
15 mana · 12 s
Heals you for 25%, +1 clone.
15 mana · 20 s
Heals you and 3 allies for 20%, +1 clone.
20 mana · 18 s · 15 m area
180% damage, +1 clone.
12 mana · 10 s
240% damage to up to 4 enemies around the target (7 m), stuns, distracts.
40 mana · 20 s · 7 m area
Six mirror copies of your foe appear round it: everything in 6 m is stunned for 2 s and burns in your colour, then they collapse into a black hole and explode (220%).
0 s
Six copies stun everything in 8 m, draw them into a singularity and burst for 270% damage to up to 9 enemies.
0 s
Six copies tear a hole in space and time: 10 m stun, a crushing vortex, and a 320% blast on up to 12 enemies.
0 s
Veil yourself and 4 allies: invisible for 3 s and +25% defence for 10 s.
30 mana · 35 s · 12 m area