So, while the sleeves hold up well to shuffling, misshuffling (catching an edge in the open part of the sleeve) is likely to destroy the sleeve with ease
It's not hard to see why Phyrexian Arena is so popular in Commander
They are more of a product to help people get into playing the game, rather than collecting cards for rarity
Like most Pokmon cards, the value of Noivern-GX depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Burning Shadows)
Desolation Twin is really two 10/10 eldrazi hiding in one card
Synergy with flickers and discard payoffs like Tinybones, Bauble Burglar, Entropic Battlecruiser and Waste Not, then backed up by counterspells and alternate plans like control, reanimator and wheels