A few notes about some of the abilities
From my experience behind the scenes with Pro Tour testing teams, their Limited specialists want to get to the last milestone and maybe knock out a few stretch goals if they can
One could argue that Jumbo Cactuar is not broken at all, and that there are already some very powerful cards that can single-handedly win a game even without 10,000 power, and that is true
Paying three black to draw 7 and then an additional black to get those 7 cards will cost a lot of life, but it seems like in most scenarios you will get pretty insurmountable card advantage out of that, and 7 life will be worth it
With just two copies in the graveyard, theyll each cost just one red mana
Three Visits is the silliness that Monty Python brings to Magic