With Doubling Season in play, Planeswalkers will enter the battlefield with double the normal amount of loyalty counters, and the curve is perfect: turn 5 Doubling Season, turn 6 play Teferi, Temporal Archmage, which will enter the battlefield with double the loyalty, and you can instantly get your emblem, which will stick around until the end of the game and just make things silly
Most stock tuck cartons, countertop boxes, and display trays are designed around this footprint
Anything useful you do before this only makes it more brutal
While cards like Mind Sculpt and Maddening Cacophony do more, they cost more
Its not uncommon to see weird stats, one-of-a-kind abilities, and other powerful effects
It also self-combos as you know, because it'll sacrifice a Forest or Plains for any land