Illusion: Greater Spellpower

Illusion: Greater Spellpower video preview: https://youtu.be/vkgf91J8CqU?t=4m50s

Other Illusions:
Illusion: Berserking Berserking: https://youtu.be/vkgf91J8CqU
Illusion: Battlemaster Battlemaster: https://youtu.be/vkgf91J8CqU?t=0m21s
Illusion: Spellsurge Spellsurge: https://youtu.be/vkgf91J8CqU?t=0m41s
Illusion: Blood Draining Blood Draining: https://youtu.be/vkgf91J8CqU?t=1m12s
Illusion: Mending Mending: https://youtu.be/vkgf91J8CqU?t=1m29s
Illusion: Agility Agility: https://youtu.be/vkgf91J8CqU?t=1m47s
Illusion: Mongoose Mongoose: https://youtu.be/vkgf91J8CqU?t=2m04s
Illusion: Hidden Hidden: https://youtu.be/vkgf91J8CqU?t=2m28s
Illusion: Jade Spirit Jade Spirit: https://youtu.be/vkgf91J8CqU?t=2m37s
Illusion: Unholy Unholy: https://youtu.be/vkgf91J8CqU?t=2m50s
Illusion: Landslide Landslide: https://youtu.be/vkgf91J8CqU?t=3m06s
Illusion: Fiery Weapon Fiery Weapon: https://youtu.be/vkgf91J8CqU?t=3m22s
Illusion: Executioner Executioner: https://youtu.be/vkgf91J8CqU?t=3m44s
Illusion: River's Song River's Song: https://youtu.be/vkgf91J8CqU?t=4m03s
Illusion: Lifestealing Lifestealing: https://youtu.be/vkgf91J8CqU?t=4m23s
Illusion: Crusader Crusader: https://youtu.be/vkgf91J8CqU?t=4m38s
Illusion: Greater Spellpower Spellpower: https://youtu.be/vkgf91J8CqU?t=4m50s
Illusion: Elemental Force Elemental Force: https://youtu.be/vkgf91J8CqU?t=5m17s
Illusion: Power Torrent Power Torrent: https://youtu.be/vkgf91J8CqU?t=5m28s
Illusion: Striking Striking: https://youtu.be/vkgf91J8CqU?t=5m45s

It changes colour when illuminated.

i.e. if you stand next to a fire it gains a yellowish/greenish hue.

edit: Actually, the colour changes the farther/closer you are to the light source, from (far)Blue>Purple>Pink>Yellow>Red(close)
edit2: This might be a pre-patch update since I've never noticed it before.(can't believe noone else noticed it either)

Will submit screenshot as proof.

Not really, it CAN be enchanted on other 2h weapons.