It changes the math of each turn enough that it requires some double-checking and re-evaluation, which can be a little frustrating for a new player who is still trying to figure out what their cards do
Ability Cost Reducers: Biomancer's Familiar, Zirda, the Dawnmaker, Heartstone Tap Slivers for Mana: Manaweft Sliver, Gemhide Sliver, Cryptolith Rite Haste: Cloudshredder Sliver Sac for Mana: Basal Sliver Infinite mana by itself: Mana Echoes Uses for infinite Slivers: Lavabelly Sliver - Deal infinite damage, gain infinite life Dormant Sliver - Draw infinite cards Harmonic Sliver - Destroy infinite artifacts and enchantments Constricting Sliver - Exile infinite creatures Necrotic Sliver - Destroy infinite permanents Sliver Overlord - Use the infinite mana to play the whole deck
What's more, it seems like TPC is trying to keep pushing out ex cards for new Pokmon, even if its not making a big song and dance about it
In less than 1% of boosters, this slot is replaced with a traditional foil acorn Alchemy card
VIVI ORNITIER Vivi Ornitier is the most infamous Commander in the set, and many folks are already trying to break him wide open