Board Thread:Warhammer 40k General Discussion/@comment-25618639-20150220210346/@comment-6078851-20150328155028

yeah, that's also mentioned in the codex, but it didn't destroy the hive fleet - it did suck in quite a few ships but in essence it trapped the remains of the hive fleet between the vortex and the imperial ships, and there was still a lot of fighting required before the hive fleet was defeated.

i doubt the shadow in the warp is capable of sealing such warp-rifts as they are pretty much just holes that have been blown through realspace into warpspace. i think the shadow in the warp can seal a rift if it's actually active and psykery is being directed through the rift, as in daemonic incursion, as such the shadow can smother such psykery thus sealing the rift.

obviously such rifts like the eye of terror are simply too vast to be smothered but, the shadow in the warp continues to grow as more and more tyranids awake from their intergalatic slumber, and i wonder if, when every tyranid is awake, the resultant scope of the shadow may reach a scale to threaten such rifts, and potentially threaten directly the gods themselves.