Spider Replicant seems... confusing? Should it simply read something like 'when Spider Replicant is put into a graveyard from play, you may sacrifice an artifact, if you do, return Spider Replicant to the battlefield.'? Or is there some reason you don't want the ETB trigger? This version also doesn't have the strange interaction of gaining any +1/+1 counters that were on the target artifact. You could add that line if it was important.
I suppose the question is what are you trying to with this card in broad terms?
Hybrid mana Thought Scour seems cool.
Chainhaunt Gaoler seems boring, but effective. Is the ability to tap down artifacts a big deal?
The two Wrath variants are pretty cool in idea, but pretty weak. On Vaporization Trial, I am not sure how many cubes are slow enough to be considering
Decree of Pain, but I suppose taking a mana off the cost in exchange for colour intensity is pretty fine. I presume the ideal follow-up with Chain Reckoning is a token producer, which makes it pretty comparable to something like
Kirtar's Wrath or
Phyrexian Rebirth, gaining the flexibility of being able to cast a card draw spell, or something else afterwards seems worth the increase in colour intensity. All of the comparator cards that I have listed are pretty weak though, so you have some room to manoeuvre if you want.