This here shows a list of the many mentors that Dimitri was trained by in the past who some also happen to be in the present who were sent by Aku the same way Dimitri did.

Red Haired Shanks
Puss in boots
Kratos
Mimir
Aang
Master Oogway
Master Shifu
Kuai Liang
Hanzo Hasashi
Urbosa
Revali
Daruk
Mipha
Link
Týr
Brok
Sindri
Jinbei
Fire Fist Ace
Whitebeard
Kozuki Sukiyaki
Grand Master Dashi
Master Monk Guan
Chase (before he turned evil)
Goliath
Monkey D Dragon
Merida
Sun Wukong
Garnet
Pearl
Rose Quartz aka Pink Diamond
Bismuth
Vegapunk
Esdeath
Thor Odinson
Iroh
Hephaestus