Pithing needle didn't work well for Tron?

It was underwhelming at best.

Ack. Have you tested playsets of molten before? Does it mess up other matchups?

I board it in vs burn, ad nauseum, storm to shut them off colors when blood moon isn't there.
If anything I used to never board them in and now I just bring them in about as often as I do rabblemasters

Good point, I guess a playset won't hurt. I'm shocked though that you didn't get as much miles from pithing needle as I thought you might. How about crumble? Is this your first time testing the one off or do you already have experience playing it?

Well I was impressed by Crumble last night so I'm going to test 2 copies

Oh wow so what will you cut? Are you gonna go 3 molten 2 crumble? I guess it's practically the same speed as molten rain if you cast mindstone t2

Yeah 3 rain 2 crumble or for flavor sowing salt

Lolz I think I still have one of those

Hey, linked here from an old Reddit post...have you ever tested Fulminator Mage? My list currently runs 3 Molten Rain's in the main and I'm thinking of testing the Mages in there place to get some chump blocks or damage in while maintaining the land hate. Only downside is not hitting basics though. I'm on the fence overall, what are your thoughts?

IMO:
It's not exactly meeting up with the philosophy of style of Big Red, which is the route we should go IMO. If you want to play fulminators, molten rain, and blood moon I think you'll do better playing something like RG Ponza.

Now to directly answer your question:
Molten rain is just the better choice because it can hit basics and helps us lock the opponent our of colors when Blood Moon is in play, Fulminators at that point is a 3 mana 2/2 (and we just have better options from there). Plus land destruction is good until you play against a deck that can operate off of very little if any mana at all (affinity, merfolk,Death and Taxes, and ect).

Hey I just read an old Reddit post of yours when you were testing demigod of revenge. What led you to remove them from your current list? What did you replace them with?

I experiment a lot with my list and actively keep this page updated. I still pull out demigods every now and again but it's never really been a mainstay by any means.
I mostly play them for the fun of it and to remind myself that's it's still a very viable strategy, but the tradeoffs is that you make the blue control matchup a little worse since you cut the mainboard Relic of Progenitus.
I also feel as a primer maintainer I need to maintain at least some knowledge of all the different builds so I tend to carry around just about every variant in a little black ultra pro box I share some of it here it's changed a small amount since then.