Argument 1

1. A perfect being would be able to save beings from at least some evils.
2. A perfect being cannot save beings from at least some evils if a perfect being cannot exist in a world with some evil.
3. If (1) and (2), then a perfect being can exist in a world with some evil.
4. Therefore, the existence of some evil is compatible with the existence of a perfect being.

Argument 2

1. A perfect being would be able to save beings from horrific evil.
2. A perfect being cannot save beings from horrific evil if a perfect being cannot exist in a world with horrific evil
3. If (1) and (2), then a perfect being can exist in a world with horrific evil.
4. Therefore, a perfect being can exist in a world with horrific evil.

Argument 3

1. A perfect being would be able to save beings from all past, present and future evils.
2. A perfect being cannot save beings from all past, present and future evils if it cannot exist in our world.
3. If (1) and (2), then a perfect being can exist in our world.
4. Therefore, all past, present and future evils are compatible with the existence of a perfect being.

The idea on which these arguments build is roughly the following: A perfect being would be able to save us from evil (it would be a perfection / would plausibly be an attribute of a perfect being), but it cannot do so if it cannot exist in a world with evil, so the existence of evil must be compatible with the existence of a perfect being.

The possibility of evil thus flows / may flow from the nature of a perfect being. A perfect being can only save from evil if there is a possible world in which evil exists.