The first time you get a D-Link, It will be at level 0, and therefore has no special abilities yet. One should note that, until it levels up, there will be two black circles in the lower left of the D-Link's Character's Avatar, symbolizing the abilities that still need to be unlocked. Once the D-Link levels up to level 1, The first ability is unlocked, and new commands to the deck as well. The ability differs from summon to summon, since increasing damage to decrease the falling speed, but they aren't as effective as the second level ones.