With the release of the E-Series, it became 9 cards per booster 5 commons, 2 uncommons, 1 reverse holo, and 1 rare
Just because its natural doesnt mean its healthy
If adding a single red mana one time for free is too good for Modern, then cards that repeatedly offer free mana (Chrome Mox, Eye of Ugin, and Mox Opal) or offer a one-time burst of more than one mana (Seething Song and Summer Bloom, which was primarily used as a ritual with bounce lands in Amulet of Vigor decks) are too good as well
Shark Shredder, Killer Clone Shark Shredder, Killer Clone mixes a sneak ability with a saboteur ability that steals stuff, so of course it fits in with ninja decks helmed by TMNT commanders and Yuriko, the Tiger's Shadow
At the beginning of your end step, create a 5/5 green Wurm creature token