What this would do is increase the scale of existing upgrades, for example Absorption 2 would be 3/4 hearts instead of 2 and the Arrow Upgrade 2 would do the same 3x3 but have a random chance to break blocks up to 5x5 around them.
Also a new upgrade would be added, the Curse Antidote. It would cost 200 coins and would put the Flagbearer up to five hearts. Level 2 if this would be 7 hearts, costing another 250 coins