Priest talent · row 3 of Shadow, from level 20 (15 with Talented 5/5) · Shadow

Mind Flay Rank 1

Mind FlayRank 1

45 Mana20 yd range

Channeled

Assault the target's mind with Shadow energy, causing 63 Shadow damage over 3 sec and slowing their movement speed by 50%.

Game files · build 1.60.1.70245Read from the WoW Forever beta client, build 1.60.1.70245.

Compared with Classic

Classic tooltip

Assault the target's mind with Shadow energy, causing 75 Shadow damage over 3 sec and slowing their movement speed by 50%.

Data	Classic	Forever
effect 1 spell power coefficient	0.15	0.167
effect 1 value	25	21

What Blizzard said about Mind Flay, each line checked against the files.

Matches the files
Improved Mind Flay: New row 3 talent. Requires Mind Flay. Increases the damage and range of Mind Flay but reduces its movement speed slowing effect.
The files Shadow row 3, behind Mind Flay (talent edge). The tooltip adds 10/20% damage and 5/10 yd range, and the slow drops from Mind Flay's 50% to 35/20%.
Improved Mind Flay Mind Flay Class deep dives: Priest and Warrior

69876 Sep 16First beta build we archived. No changes in the client files since.