First, none of the winning decks right now are in Rakdos colors
Madness effectively gives all of our cards Flash, provided we have a discard outlet, and all three of these work extremely well to stop creatures swinging at us, with Withering potentially hitting targets that won't
You would initially get 3 gnomes tokens from the enters effect, then Saheeli makes a copy with base power 5/5 with three additional +1/+1 counters, making you eight more gnome tokens
The utility of this spell is incredibly diverse, and even if it has no use, it can replace itself for two mana
If your payoff is gone, you can keep looping it, but it won't do anything
Most emphasize aggression in one way or another, and tackling your opponent head on with powerful (or insidious) attacks is par for the course