SoulbondSoulbond is a keyword that represents two triggered abilities. “Soulbond” means “When this creature enters, if you control both this creature and another creature and both are unpaired, you may pair this creature with another unpaired creature you control for as long as both remain creatures on the battlefield under your control” and “Whenever another creature you control enters, if you control both that creature and this one and both are unpaired, you may pair that creature with this creature for as long as both remain creatures on the battlefield under your control.”
A creature becomes “paired” with another as the result of a soulbond ability. Abilities may refer to a paired creature, the creature another creature is paired with, or whether a creature is paired. An “unpaired” creature is one that is not paired.
When the soulbond ability resolves, if either object that would be paired is no longer a creature, no longer on the battlefield, or no longer under the control of the player who controls the soulbond ability, neither object becomes paired.
A creature can be paired with only one other creature.
A paired creature becomes unpaired if any of the following occur: another player gains control of it or the creature it’s paired with; it or the creature it’s paired with stops being a creature; or it or the creature it’s paired with leaves the battlefield. (CR 702.95) (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as this creature is paired with another creature, both creatures have
first strikeFirst strike is a static ability that modifies the rules for the combat damage step. (See rule 510, “Combat Damage Step.”)
If at least one attacking or blocking creature has first strike or double strike (see rule 702.4) as the combat damage step begins, the only creatures that assign combat damage in that step are those with first strike or double strike. After that step, instead of proceeding to the end of combat step, the phase gets a second combat damage step. The only creatures that assign combat damage in that step are the remaining attackers and blockers that had neither first strike nor double strike as the first combat damage step began, as well as the remaining attackers and blockers that currently have double strike. After that step, the phase proceeds to the end of combat step.
Giving first strike to a creature without it after combat damage has already been dealt in the first combat damage step won’t preclude that creature from assigning combat damage in the second combat damage step. Removing first strike from a creature after it has already dealt combat damage in the first combat damage step won’t allow it to also assign combat damage in the second combat damage step (unless the creature has double strike).
Multiple instances of first strike on the same creature are redundant. (CR 702.7).