Pointed Discussion

You basically HAVE TO have these and Homing Sliver in your sideboard of all sliver decks.

efficiency makes it only useful against blue decks

It could find use with a reverse Blood Funnel in the mainboard. Then again, about anything which acts like Blood Funnel is utterly unplayable without a combo card.
I guess just using this guy in the sideboard of a common Sliver deck should proof to be the best idea.

A note on the flavour text and hindsight: Its kind of ironic that the slivers resurfaced and actually flourished during Time Spiral... a set based on a (temporal) apocalypse :)

Frenetic Sliver to deal with white.
Root Sliver to deal with blue.
Crystalline Sliver to deal with black.
Ward Sliver to deal with red.
Toxin Sliver to deal with green.

It would take another colour pie to stop the slivers now.

The Slivers didn't survive the Apocalypse caused by the phyrexian invasion of Dominaria They were then resurrected and faced the mini-Apocalypse brought about by Karona's creation, and barely made it through alive. Finally, during the Apocalypse of Time Spiral, the slivers had learned to cope with end-of-world scenarios and ignored the whole shebang. At this point, I don't think there's an Apocalypse big enough to stop them short or total planar collapse.

Forget Cavern of Souls. Run this instead. Be a bro.

Eat it, blue. 4/5