Rotshell, Rakthak's Nest

Ward {x}, where X is the number of +1/+1
counters on Rotshell, Rakthak's Nest.

You may cast creature spells for {2} less. If you cast a
creature spell this way, sacrifice it when it enters the
battlefield.

Whenever a creature you control dies, put a
+1/+1 counter on Rotshell.

An incomplete ritual does not lack a byproduct.