I've never been a Slaine fan. The character doesn't work for me. Theoretically, he's one of 2000AD's more interesting creations... but, in practice, I've never been able to believe in him or his world. He doesn't come alive to me as a real person in a real story.
IN PRINCIPLE: Slaine's an attempt to turn Celtic mythology into modern comics, complete with the extremely weird worldview you'll get if you read up on the era in Pat Mills level detail and take all of its legends literally. This is extremely Mills. It's almost preachy in how hard it's selling neo-pagan civilisation and beliefs, e.g. sacred matriarchy and lots of mind-bending ideas like the king who's only got seven years to rule before as per tradition he's ceremonially murdered, or the Muster.
"Under this ancient law, the last to arrive for a battle was executed in honour of the goddess. It also encouraged punctuality." And, yes, we see Slaine carry this out. Most of this stuff is so weird, in fact, that I bet most of the audience never guessed that it was based on actual mythology and culture. You'd think it was just Pat Mills going over the top again.
(Slaine was just a Conan clone in his earliest 2000AD stories, mind you.)
IN PRACTICE: Slaine only intermittently feels like a real person and his stories only intermittently feel like real stories. That's the downside of drawing directly from legends. Storytelling doesn't work the same way in those. Whenever I read Slaine, I get the impression of a pseudo-protagonist being directed by the Hand of Puppetmaster Author to do stuff that doesn't matter in a world that doesn't feel real.
Ukko feels real, mind you. Ukko's great. Ukko's a money-grubbing scumbag who manages to be revolting both to his contemporary Celts and to the modern audience. Ukko makes the whole thing human... at least a bit. When he's around.
This particular Slaine saga, though, was huge. To quote the introduction to the 2008 Rebellion graphic novel:
"The Horned God was a huge hit for 2000AD. It is not only the most successful graphic novel 2000AD has ever produced - the only one to be a runaway bestseller in Europe - but sales of 2000AD itself actually shot up while it was running in the comic."
It's by Simon Bisley, you see. The guy's a megastar, although I don't think he's drawn many comics lately. Bisley was the first Slaine artist to use paint... and holy cow. His range is amazing. He can draw beautiful ultra-realistic work, but also outrageous caricatures. He'll hop between media on the same page. What distinguishes him from equally gorgeous Slaine artists like Glenn Fabry and Dermot Power is his playfulness. He's more experimental than almost anyone, to the point where one's almost tempted to suggest Mick McMahon as a better point of comparison.
As for the script, it's quite interesting. I personally still have that Slaine-distance from the page, as described above, but Bisley's capable of putting so much personality into Slaine himself that I'll be able to believe in him for a panel or two. I quite like Mills's explicit subversion of heroic myth, which he ties into the mother goddess, the positive case for devil worship and a very enthusiastic kicking to patriarchy (even in the Iron Age by druids). It's fascinating, even if also at the same time a bit boring. The story's problem, I think, is that it then turns around and does lots of big battles in Book III, which are inherently less interesting. There's even a meta discussion of this by Slaine's chroniclers in the framing story.
"Nah... readers aren't interested in all that fancy stuff. What they want is plenty of hacking and slaying."
"Yurrr... I like hacking and slaying!"
"But there's always been more to Slaine than just some muscle-bound barbarian. It's an attempt to redefine the hero, to convey the matriarchal origin of myth."
"Take a tip from an old hack, dear, and stick to Slaine chopping off brainballs!"
"Yurrr! I don't like the comp... comp... complicated bits. I only like it when he's killing people."
(For what it's worth, Bisley was in the latter camp. He'd really wanted to draw Conan and I read an interview once where he said he didn't like Marshall Law because he thought Mills was getting too savage and polemical with it. Bisley thinks comics should be fun! That said, though, he still served this story excellently.)
There's a lot in these pages and they're definitely worth rereading, given the richness of Pat Mills's ideas. It's on the playing field of literature and there's no comparison between this and some random 2000AD series like, say, Sam Slade Robo-Hunter. As weekly episodes in the magazine, this would have been mind-blowing. But even so, for me... naaah.