pokemon vibrava card Scarlet and Violet Surging Sparks #206/191 Illustratio – Rotterdam Comics Colorless Artist Pokemon Card - D&P: Secret

Doubling Season Doubling Season is the best doubling season type effect because it only applies to your cards

If youre gaining life, this mere 1-mana card already gives you Cat tokens

That's only card draw and this replaces itself and casts things for free each turn and thus impacts the battlefield and gives you uncounterable stuff too instead of drawing you cards and you save mana too so you can cast with discover and then save your mana for instants or tap out for two turns of mana usage from your main phase and this in one turn

Market research showed that hybrid mana was the highest-rated thing in the original Ravnica block, and I believe it is still one of the highest-rated "mechanics" (it's a tool, not a mechanic, but that's what the market research called it), if not the highest, of all time