Link Rules

To put a Link creature onto the battlefield from outside the game, you must sacrifice all cards
on its requirements. Creatures with Link have a
converted mana cost equal to its Link Number.
The Link Number is equal to their original
toughness. If a creature has X toughness, it
has a link number of X. If a creature gains or
loses toughness, it's Link Number remains the
same. When sacrificed this creature counts as an
amount of creatures equal to its Link Number
of its types, colors and name.