Diabolical Adiabatic Multiverse

I can close myself off

I've done it before

Become self-contained

An adiabatic system

Nothing lost

Nothing gained

We come together

We break apart

The multiverse weeps

For a diabolical heart

Too many a time scorned

I implode again

A singularity forgotten

My horizon

My end

Thanks to @HerbertHitchens for these words