I of course mean these decks: Born of Fire, Hidden Depths, Crushing Current.
When these decks were released, they were soon nerfed because back then they were too good for the Theme Deck format (indeed they were). However, since then plenty of Theme Decks have been released that are a lot better (almost all Sun/Moon Theme Decks after the initial 3). Therefore I'd like to suggest to un-nerf the decks back to their previous states.
This would give new players some more of a fighting chance (while still losing enough to make them interested in purchasing new Theme Decks), the old versions of those decks were more fun to play (such as no more useless fillers like Psyduck and Porygon), and more people would be interested in playing those decks resulting in more variety in the Theme Deck format.