Do not delete these, even after you install them (some are used by the GUI)
In theory, this change shouldnt actually matter too much in the grand scheme of MTG
Of course, four mana is a much steeper investment than Brainstorms single-mana cost, so Jace really only pays off in the long run
It's more fair in Commander, where it feeds Landfall decks and ensures they have a constant flow of fetchlands to trigger their effects
However, this does look like it might be worth playing in the Black-Red deck, as there is one red Sacrifice effect at Uncommon, two black sacrifice effects at Common, and one at Uncommon, so setting up the sacrifice is actually going to be doable there, making the card a solid playable in a deck that gets its hands on some of those effects
One of the best MTG commanders ever released, the original Edgar Markov may not feature on any cEDH tier lists, but it can absolutely stomp a regular EDH table