The July 21st, 2021 patch introducted a whole new roster of Overseer Agents. Please note that these appear at the BOTTOM of your Agent listing.
Here's a checklist for your reference:
Elite (Purple): 2**
Avatar of Bristlebane
Avatar of Xegony
Rare (Blue): 12
Enynti
Founy Jestands
General Jyleel
Juline Urncaller
Maesyn Trueshot
Niola Impholder
Nitalla
Sister Daria
Sylia Windlehands
Tobon Starpyre
Yeolarn Bronzeleaf
Xicotl
Uncommon (Green): 12
Avenging Catiff
Black Dire
Disciple of Tunare
Dryad Tender
Felwithe Armorer
Imp Familiar
Kaladim Brewmaster
Kaladim Surveyor
Koada`Dal Noble
Stalking Fury
Warden of Tunare
Weapons Trader
Common (Grey): 24
Acidic Ooze
Ak`anon Architect
Blood Wolf
Cauldron Rat
Dwarven Theoligist
Elder Spirit Guide
Faydark Nightgazer
Feir`Dal Salvager
Felwithe Guard
Felwithe Songwhisperer
Felwithe Sunreaver
Impetous Rover
Koada`Dal Alchemist
Koada`Dal Counselor
Koada`Dal Diviner
Rock Spider
Shadowmane Brawler
Sylvan Bat
Sylvan Pilgrim
Teir`Dal Marauder
Treasure Seeker
Undead Knight
Undying Magus
Wasp Worker
** there are 3 purple agents not yet available.