It has been removed sadly. Was the wish of the creator of it after the game got leaked.
A similar style will show up eventually to replace it, but the exact same thing but wont be there.
Ahh, hopefully it comes in soon. Legit enjoyed how fun it was to scale the Hero card into its final form.
A.E.R.A is probably the closest in terms of similar scaling mechanic
Yeah, its actually my second favorite deck but it doesn't hit the same due to the Hero Deck starting out as a weak combo deck that scales very hard.