SC2Mapster

Use a Unit Filter validator on the buff that checks the unit spawned (via the create unit effect) is not dead.

Else place a hidden buff on the summoned unit via the create unit effect that then applies your other buff to the caster and have the caster buff be validated for the other buff using the source of the apply behaviour effect as a frame of reference.

Number 2 and 3 are just using Damage effects to kill the unit instantly

Need more details as to how you want to summon your guy.

In short I assume you create your summon using a Create Unit effect. Under that effect is a field called Effect - Effect - Spawn. You find that hallucinations and broodlings use that field to apply buffs to the created unit. Use an Apply Behavior effect to apply a Buff type behaviour to the summoned unit. Under the buff on the summoned unit in the Effect - Effect - Initial field use an Apply Behavior effect to apply a Buff type behaviour to the caster via the Unit - Unit - Value field of the Apply Behavior effect. On the second buff use a Unit Compare Behavior Count validator to remove it if the summoned unit no longer has it. This is done by Validator - Unit - Effect field being set to the effect that applied the buff to the caster so you can use the source of it as a frame of reference to validate the summoned unit that applied it. The Effect - Effect - Final field of the summon buff can have a Damage effect with the kill flag that targets the source so simple removal of the buff kills the summon.