So after you upgrade his power close to the close the portal stage where you need to buy 5 minions after doing it the first time you can no longer power up your minions again.
You unlock the hero power “Close the portal”
You buy 5 minions in one turn and while buying each minion it countdowns till you hit 5
Then it buffs all minions +2/+2
However the hero power stops working after you do this once.
So then next turn when you try to once again buy 5 minions there is no count down when you buy minions.
And nothing happens when you buy 5 minions.
The hero power says this is repeatable but it doesn’t seem to be.