One of my earliest Mk. 2 Warmachine memories was playing Deneghra one and getting blasted by a Repenter, dying over two turns to fire rolls. They seemed utterly ridiculous at the time... and in Mk. 2, I wasn't really wrong.
Repenters were a long time Protectorate staple, representing very much a core concept of how the Protectorate worked. A bit short range, but good damage spray with continuous fire. Costed at a pretty reasonably 8 points, you can get a lot done with the little Repenter... and truthfully, I'm uncertain why they aren't used a little bit more often these days.
Repenters bring a relatively cheap but effective spray to the table. While sitting at RAT 5, they boast a POW 14 roll when buffed by Battle, which is nearing the damage territory of heavy warjacks. As a spray, it can't be stopped by shield guards and can hit multiple targets at once, as well as ignoring things like stealth, concealment, and cover. Sprays are quite powerful, and Repenters bring a pretty good one to the table. Further, they light their target on fire and do fire damage, which synergizes with many Protectorate tools.
They also boast a base PS 13 melee attack which is common to almost all of our light warjacks, which of course is also buffed by choir to be in the realm of damage output brought by many cheaper heavies. Additionally, the Repenter has a chain weapon, which I've found to be applicable more often than you'd think. You can consider him PS 17 against enemies with shields, 19 against shield wall, which is a pretty great place to be. Throw an additional buff like Ignite on there and he'll actually mess up hard to crack heavies (I had one leave a Centurion on life support not long ago.) This gives them a nice dual role as a gun piece that can actually do some damage when he really needs to.
As far as the gun goes, it is quite short range. In total, a non-buffed Repenter threatens 13" with his gun, which is alright but not spectacular. Fire type on the spray means it's weak to fire immunity, which is often considered the best damage immunity and people do take it.
Repenters are also slow. A 1" melee is pretty good but they're SPD 5. This isn't a front line combat 'jack by any stretch of the imagination, and while the damage output can be pretty good, that's mostly an if you need it thing more than any kind of actual focus.
Lastly, they're a little bit paper thin but that's not uncommon for light jacks. 12/17 buffs really well with things like Defenders Ward, but you usually just have a better target for spells like that and Repenters are largely running on the choir to get them to the fight, and won't survive in the middle of things for very long. Still, at ARM 17, most lights won't take one down, so the opponent will likely be taking you down with infantry or heavies. Keep infantry off of it and you can sometimes force an expensive target to come in to fight.
Who Likes A Repenter?
The thing about Repenters is they need a little bit of help. However, with just a very small amount of help they can be seriously dangerous. You won't really see them with any random caster, but a little bit of synergy goes a long way.
Feora2 likes the continuous fire, and they don't hate escort, but I'd say there's better places.
Feora3 of course has Incite, which pushes the Repenter up to fairly crazy output potential. You can also redline it if you want, I guess?
Severius1 is pretty obvious, everything loves Eye of Menoth. Likely he'll be at best a tertiary target for his defensive buffs, but they stand alone pretty well with Eye of Menoth around.
Amon ad-Raza is one people are picking up on a little. While his kit doesn't innately help guns, Field Marshal: Parry in combination with Mobility lets you get the sprays into some pretty wild places, including into back arcs really easily. I've loved as many as three Repenters with Amon, and at the top of a synergy chain they'll still do some good work.
Reznik1 could Repenter spam pretty well, actually, with Brand of Heresy pushing them up to pretty good potential... but is only really efficient if you have a bunch of them. Worth testing, but I'm uncertain about this build type up to this point.
Kreoss loves the sprays. On feat turn they'll kill a ridiculous amount of troops or laser down hard targets pretty well. Redeemers will do better for single target damage on feat turn, but the Repenters are a little more effective on a turn by turn basis.
Malekus, of course, is the Protectorate pyromaniac and loves relatively cheap fire sprays. I love them with him, Open Fire is great on sprays (even if they're only RAT 5), and they hit like a truck on his feat turn. Plus Ignite is neat on them in a pinch.
There are a few other minor synergies (Reznik2 with Spellpiercer is great, for example, but... that's good on everything.) These are the main casters I would consider taking one or more Repenters with; I often take two if I take one, basically running them instead of a Reckoner or other 16 point heavy option in favor of a more shotgun approach with more potential damage.
I've seen Repenters start appearing in peoples lists a bit more often lately, and that makes me glad. They're great little lights with a ton of versatility; Protectorate also takes light 'jacks with guns to really strong levels, but the Repenter is the only one we have with a decent accuracy gun that doesn't need enormous help to hit a target directly. When/if we get a nice single-target light warjack gun, the Repenters role may need to be revisited but... this is our main gun light, and it's a pretty decent one in my opinion.
What lists do you like Repenters in? Have you used them much in Mk. 3? Let us know in the comments, on facebook, or on twitter!