In a multiplayer format like EDH, you can even choose which opponent is the one splitting
Mother of Runes Another card that could easily be a staple of Historic and Brawl is Mother of Runes
If youre going for pure flavor, the other versions of The Master are mostly in Dimir and Rakdos colors, so you could run them all here, in theory
While Phyrexian Censor can be effective in limiting opponents' spellcasting and slowing down their creature deployment, there are potentially better options like Thalia, Guardian of Thraben or Thalia, Heretic Cathar, which provide similar disruptive effects with additional benefits
So really a bit of power creep
The biggest challenge was that creating a number of 1/1 artifact token creatures was usually just better than adding that many +1/+1 counters to your creature, so it was hard to create designs where the two modes were balanced