Discard was used to force the opponent to overcommit to the table or to clear a path, after which the board was wiped and the resulting card advantage let you slowly finish off a helpless opponent
It also adds a few new mechanics such as Exhaust (using an ability once per game) and Speed (a new mechanic that tracks when it starts from 1 speed and only increases once per turn when an opponent loses life up to a max of 4 speed)
Chaotic Transformation I got so tired of opening Chaotic Transformation in Dominaria United Drafts where its useless, so I figured Id give it a shout-out here for some karma
This doesnt see much play (probably due to the color requirements), but I would consider running it if your deck contains these colors
And its very hard to know what colors pairs will be good after rotation
Zealous Display also untaps your creatures if it's not your turn, which is great defensively too, making your whole team surprise blockers who just got more powerful