Whether to run 2 or 3 is a difficult choice
and Hearthstone trace their roots back to MTGs mechanics
With the price steadily increasing, this card is a pretty good investment that won't break the bank by costing thousands of dollars
this turn, your opponent cannot activate cards or effects when an "Arcana Force" monster(s) is Summoned to your field
C Common The Fang of Critias X SPELL (This card is also always treated as "Legendary Dragon Critias".) Send 1 Trap from your hand or field to the GY, that is listed on a Fusion Monster that can only be Special Summoned with "The Fang of Critias" (if that card is Set, reveal it), then Special Summon that Fusion Monster from your Extra Deck
It's also very tough to permanently remove: if it dies, it returns to it's owner's hand at the beginning of the next end step, ready to cause havoc again