You want a creature to have double strike because you get the first strike damage and then another hit. Both keywords change the damage step, but double strike brings extra value and damage
Understanding card interactions, turn sequences, and specific game mechanics can provide a significant advantage
Ulamog, the Defiler might end up being more annoying than Emrakul in Casual Commander
Because these variants are restricted to the highest tier of regional tournament distributions, the available circulating supply in the ecosystem is almost non-existent
Green can provide sweet artifact hate to shut down aggressive combo decks while black offers excellent tutors, hand disruption, and removal
In other words, combo decks dont really interact with or (to some degree) care about their opponents cards