as I said. This applies for the WHOLE COUNT OF HEROES OWNED BUT INSTEAD AMOUNT OF 3 IT WILL WORK AT AMOUNT OF 1! ONCE YOU HAVE A HERO OTHER HERO ICONS WILL BE HIDDEN AS YOU WANTED! So next time please first test things others say and then reply if it fucking don't work. I don't like to post something twice.
Player - Limit training of Heroes to 1 for Player 1 (Red)
Limit heroes
Events
Unit - A unit Finishes training a unit
Conditions
((Trained unit) is A Hero) Equal to (==) True
Actions
Player - Limit training of Heroes to 1 for (Owner of (Trained unit))