Thor, God of Thunder and cost reducer - How much damage?

[[Thor, God of Thunder]]
[[The Scarlet Witch]] - cost reducer

Say Scarlet Witch is base power 2 and I’d like to cast [[Call Forth the Tempest]] (card doesn’t matter, just an example)

Regular cost is 5 + 3R, with the reducer I only pay 3 + 3R

Does Thor deal 8 damage or 6 (because of the reduced cost)?

Thanks!