It might come as a surprise but I did a quick chart to look at his melee...
I compared him to Dante and a generic Captain with 2 different weapons to get an idea of his individual combat prowess (so this chart doesn't factor in ranged weaponry or how they buff other units).
Seth is about the same as a typical Captain here, very slightly lower. Dante is obviously ahead for damage output in this category thanks to his extra attacks but the humble Captain is more point-efficient (when a melee weapon is the only upgrade).
Unfortunately bottom of the pack here. His 8 strength hits will do damage, he just lacks the AP of the other options shown. Dante again up ahead for damage, Captain for points efficiency.
This is where Seth catches up a bit. While he still has weaker AP against the higher armoured targets his fixed 3 damage per wound will come into play. He's not far behind dante vs non-characters here for damage output, though Dante jumps up if the target is a character and the hammer Captain is powerful regardless of that. In terms of points efficiency Seth is almost the same as a Relic Blade Captain when the target has multi-wounds, and does surpass Dante against non-characters.
So for me if I was taking him for his damage output there are more efficient options. Where he could add something special is his Whirlwind of Gore ability. If you throw him into the middle of a bunch of enemies with some Flesh Tearers units either side of him there's a 1/6 chance each will get to fight again in the same turn (if they survive). It's a low chance but it sure would be fun on the rare occasions that it happens!
The biggest downside for me is his lack of mobility. With no Jump Pack you're counting on a transport to get him close quickly, and if you pair him with a jump pack unit he'd struggle to follow them. If you take him with a non-JP unit to match up you're then stuck with 2 non-JP melee units, which might be ok when you first hop out of a transport but can then be a limiting factor in getting to the next preferred target.
In 7th I would run Seth and Corbulo together as they are both stuck on foot but unfortunately they can no longer buff each other.
How would I use him?
I will use Seth as I like the model and every now and then I run different characters for a bit of a change and to use models I own (like Tycho) but it will be in the knowledge that he's less efficient as a spearhead damage dealer than other options and his Whirlwind is a small chance of a bonus, not to be expected to occur at any point.
I would probably give him 1 or even 2 units to run round together - if I'm going to use him I might as well try to make the most of that low Whirlwind chance. With him being most efficient against multi-wound targets I'd maybe pair him with something like Hammer DC, see if they could kill one unit on the charge, consolidate into another to avoid being shot at and have Seth trigger the extra fight for them. If I did take an expensive unit they'd get Jump Packs though, to get them moving fast the rest of the game. Seth would then just have to keep up as best he can. They'd probably be delivered in some kind of transport, depending on the capacity needed to carry him plus the unit(s). Maybe a Flesh Tearers wing arriving in a decent size group from a Stormraven to support my main BA force?
In 7th I would also pair him with CC Scouts as his weapon was more infantry-focused and the Scouts were effetive in that role as well as providing ablative wounds for Seth. In 8th I feel anti-infantry would be a waste of his 3D so that combination is out for me.
He's a tricky one. Points-wise there are better options, but fluff-wise he's awesome and I will field him sometimes just for that! His Whirlwind of Gore will be irrelevant most of the time you play but there will be that one game one time where it triggers at a vital moment and gives you the extra damage you need to turn things round to claim victory.
Edited by Thoridon, 21 June 2017 - 10:21 AM.