I think of tcg as holding onto the past, reliving it a bit, but not a massive new territory that is unexplored with endless growth
Sometimes youll get a weird combination, like a Gideon planeswalker attacking as a creature card with +1/+1 counters and loyalty counters, and you can double both
After the rework, you will no longer be able to play the step-up battles that were available up until now, and you will no longer be able to obtain first-time rewards or battle task rewards for them
A plausible reason why this card has been the first to spike, is that Tiamat is a DnD god, and so it's unlikely to get a reprint (which would tank its value) in the upcoming universes-within MTG set
After weeks of playtesting, the team deemed the mechanic undoable