Been reading random old Batman issues as well as the recent Joker War and Three Jokers stuff. Joker War felt like a setup for Clownhunter and his future antics, almost how Hush set up Red Hood to an extent. Three Jokers is decent, interested in how they are gonna conclude it.

What series (and issues) did the Electric Superman arc occur in? More importantly than that, why is that plotline so controversial?

The first appearance of Electric Superman was in Superman #123, but the story (like most 90s-era Superman stories) had been building up for a while before that in subplots.

It's controversial because it was a massive change for the character, and any time you make a change to Superman, you're going to get casual readers who treat it like the end of the world. People thought Superman was dead forever in Superman #75, and lost their minds. Most comic fans who were reading the book, though, knew that Superman would be back before long. Superman's such a well-known character that there's always going to be a high level of interest in a status quo change.

That said... people weren't really that upset when it happened? The books sold great for a few months, becoming series that everyone wanted to follow. The story didn't really deliver, which is maybe worth noting, but it's not like it was reviled at the time.

Did they ever revisit the Electric Superman in more recent entries? More to the point, did they establish a multiversal Superman who went electric and remained as such or one who was always electric?

So the DC Future State thing, I am kinda interested. They say it is only gonna be two-months so why not. Liking the new suits, and I find it funny Grifter from WildC.A.T.S is sticking out like Deadpool in an epic "Avengers Assemble" type poster. :lolol
And Swamp Thing looks like something out of a Iron Maiden album cover.

Not that I can recall, no. It's definitely a part of Superman's history that DC seems fine with ignoring.

If there's anything that smacks of Jim Lee's involvement, it's DC spending the last nine years trying to make Grifter a thing in the DCU. So many series and team-ups! It just never works!

(Honestly, I think they'd've been better off concentrating on Zealot, like some of the early New 52 art indicated.)

Oh how I miss the Image comics during the founding years; most of them were dollar store ripoffs or mash-ups of Marvel and DC heroes yet somehow was cool for a kid at the time. I remember one time during lunch recess kids would argue over who gets to be Grifter and Warblade. :lolol
That said WildC.A.T.S was my favorite when other kids would go nuts over Spawn. And yes, Warblade for some reason was my fav despite being a hybrid of Lady Deathstrike and Omega Red with a Doc Samson green ponytail.:lolol

Since Tsuburaya and Marvel are pushing Ultraman, does that conflict in anyway, from a legal and marketing standpoint, with the "Ultraman" of the Crime Syndicate?

Yeah, kinda surprising we did not have another Shazam/Captain Marvel debate with this.

I imagine that unlike Captain Marvel it would simply be very, very hard to have a case against Ultraman when it's a very, very well pre-established franchise that's been around for over 50 years and is a massive cultural cornerstone backed by a very very rich company.