Bloodbrothers

Children of the Night (When this creature dies,
create X red and white 1/1 spirit creature tokens with vigilance, where X is the number of +1/+1 counters
on this creature.)
When this creature enters the battlefield, create a
1/1 red and white vampire creature token with
'When this creature dies, put a +1/+1 counter on target creature you control.'

Inseparable, even through the veil of death.