This coating affects: How easily cards slide past each other in a sleeve How well the image quality holds up when cards rub together How much dirt, sweat, and table grime they can handle before looking rough How light reflects off the surface when you tilt cards under a lamp or UV light Foil MTG cards add another layer of complexity
In addition to serving as flexible removal and a massive body in combat, this creature immediately puts your opponents on a timer, as whenever Ulamog attacks, you exile the top twenty cards of the defending player's library
Getting to nab something like Terastodon can alter the game dramatically
Multiple Battles make it really hard for your opponent to use interaction to mitigate the natural four token pattern of Battle for Bretagard, and if you wanted to trigger the last chapter of Battle for Bretagard once, you certainly would love a second helping of copying tokens
As such Mongrel is pretty weak in cube these days and not the sort of thing you are looking for in a cube discard outlet