This is Impactor, Marvel UK's leader of the Wreckers. Decades ago, I would have had to explain who he is to essentially everybody, as well as what the "Wreckers" are, but after both entities were ported over into the IDW comics (and after the Wreckers were a staple of BotCon fiction before that), they're not quite the unknowns they were in the United States that they once were.
In the original Marvel UK Transformers stuff, Impactor was the upright and outstanding leader of the Wreckers, an Autobot special missions task force that was made up of all the left-over toys that couldn't fit anywhere else. He died heroically, Springer (a real toy!) took over, and Springer spent the rest of his days lamenting that he would never be as good a leader as Impactor was. With a quick interruption, of course, when Impactor was
In the current IDW comics, Impactor was still the former Wreckers leader, but because he was killed, but because he was disgraced. You see, maybe leading a team of "we do the dirty work so you get to keep your hands clean" red-shirt commandos is probably mentally taxing? Probably? Anyway, modern Impactor is a little more anti-hero than the original. He was jailed for war crimes, but now he's out and about and trying/failing to live up to Springer's more-heroic example. It's the ol' switcheroo!
And now he has a toy! Well, sort of his second toy. Depends on how your brain categorizes these things. Fall of Cybertron gave us an Impactor toy, but that Impactor technically belonged to the Aligned (Transformers Prime) universe, not Generation 1. But like that toy, this Impactor is a head-retool of a combining figure. And as a plus, he's actually in Impactor's colors, rather than having them inverted and changing his yellow to orange. Also, this time he's a GOOD TOY? Like, Rook is easily the best Deluxe of the Combiner Wars line. He can do everything everyone else can do plus he has the ability to have Hulk Hands and he has articulated feet. Thus I welcome our new Impactor overlord.
In addition to the new head, Combiner Wars Impactor comes with Generations Arcee's arsenal of weaponry. You might think at first that this is pretty weird, since all these weapons really only work with Arcee, who doesn't have 5mm peghole hands. Well, turns out they work fine with Impactor, too! The tabs are 5mm across, so they can fit into his wrist-gun pegholes fine enough, plus there's like a field of slots on his backpack that just so happen to accomodate the onslaught of tabs that Arcee's weapons possess. So there you go.
Really, the only negative this toy has is that it's a little short to be a perfect Impactor toy. Impactor should, in a perfect world, be the next size class up. But otherwise, this is a great Impactor made from a great toy. In that respect, he's very satisfying.