Ripper Swarms

During the Declare Battle Formations step, if every model in a unit has this ability, you can set it up in Reserves instead of setting it up on the battlefield. If you do, in the Reinforcements step of one of your Movement phases you can set up this unit anywhere on the battlefield that is more than 9" horizontally away from all enemy models.

If a unit with the Deep Strike ability arrives from Strategic Reserves, the controlling player can choose for that unit to be set up either using the rules for Strategic Reserves or using the Deep Strike ability.

If your Army Faction is TYRANIDS, while a TYRANIDS unit from your army is within 6" of one or more friendly SYNAPSE  models, that TYRANIDS unit is said to be within Synapse Range of that model and of your army. While a Tyranids unit from your army is within Synapse Range of your army:

■ Each time that unit takes a Battle-shock test, take that test on 3D6 instead of 2D6.
■ Each time a model in that unit makes a melee attack, add 1 to the Strength characteristic of that attack.