Kuan-Xi's Guide to Sorcerers

Water

• Shen Gao - The Municipal Sorcerer in the Dragon's Throne
• Aoki Tadako - Weather sorcerer, super Shrouded Isle patriot, not fond of Dragon Army
• Ni Junxian - Elemental Braid
• Yun Ling - Master water sorcerer who works for the Port of the City of Light
• Okura Yosai - The Firelord's guy
• Great Wave Tseng - City of Light
• Ho Kuan-Xi
• Cao Caihong - the Green Duke's water sorcerer, met during Grata,

Earth

• Eternal Redoubt - Elemental Braid
• Stoneback Cho
• Huan Ken - of the Winter Academy
• Tsu Fa - Dragon Army earth mover

Fire

• Lady Suzuki - Kuan-Xi's mother
• Yuwen Fire-Eye
• Zhantai Yuwen Fire-Eye's apprentice
• Ming I aka Wu Wangmu
• Dorga - Fire sorcerer ghost from the Forest of Chin encountered in Ghost Hunters
• Qili Hu - from Yang Shen-Ji and the Goblet of Fire
• The Elemental Braid had a fire sorcerer in Fruit Fight, but I couldn't find the name.
• Inspector Di
• Kusuhara Romi - the Shrouded Isle Regent is said to be a fire sorcerer
• Dishi Delun - The Yellow Duke's fire sorcerer, from Grata

Metal

• Master Bai aka Bai-Jiao of the White Lotus
• Hsu Verity - Elemental Braid
• Renilo - Hsu Verity's apprentice, met in The Price of Good Fortune
• Yang Shen-Ji
• Ezokin - Moneymancy
• Orefinder Liren - from Yang Shen-Ji and the Goblet of Fire

Wood

• Ebon Brush - from Yang Shen-Ji and the Goblet of Fire, Jia-Jia is her daughter, deceased
• Sasaki
• Autumn Rose Nameomancy
• Cartogramancer deceased
• Mu the Mad - met in Amateur Necromancy

Notes and other sorcerers

• Hao Hento - ritualist for the Upward Line (no element listed in log)
• Jia-Jia - Shen-Ji's daughter, pictomancer(what element is that?)
• Sa Zhenren - the only sorcerer known to use lightning (under consideration)
• The Purple Duke's mage, a swamp sorcerer (water/wood)

Note that the Firelord has one of each kind of sorcerer at his court, but we only know one of their names.

Fire dukes employ fire sorcerers and water dukes employ water sorcerers.

Sorcerers who work for important people seem to often have their names missing from logs. I have seen a number of references to "So and so's sorcerer" without actually giving them a name.