then everything in philosophy is special pleading because philosophy simply work like that. Then atheism is also a special pleading because "god doesnt exist" is a philosophical claim
Metaphysics tries to understand the nature of reality.
How it does this task? By physics? No. By chesmitry? No. By any specific science? No. All these sciences deal with their object focusing in only one aspect: classical physics deal with the object in terms of movement. Chesmitry deals with the object in terms of its composition
But metaphysics doesnt want a specific answer, metaphysics want a general and fundamental answer. For this reason it won't deal with an object in terms of movement or composition, but in terms of it most fundamental aspect: the object as being.
And how metaphysics do that? Through abstraction, deduction, inference, etc.
This kind of inquiry tries to analyze a concept and understand everything about this concept: its limits, what is it meaning, its real or not, its necessary or not, its relations, its category, etc. It also take some premises and try to take all necessary conclusions about these premises. If you take premise A and B you will achieve conclusion C. But if you take premise B and D you will find a new and different conclusion.
And then when the inquiry has a conclusion it will be claimed:
"Reality is this"
"Being is that"
"God exist"
"God doesnt exist"
"The universe was not created"
"The universe was created"
"Physicalism is true"
"Only conciousness exist"