While I know lots of people have posted art of them, I’m going to put some of the most recent official GW models with Eviscerators/2 Handed Chainsword here to emphasize the point.
First is the new Sister Repentia models which I think would be perfect to base a new variant on. They’re not as thick as some of the older depictions, but are still long enough to look usable but unwieldy for standard humans.
Next is a Khornate Jakhal with a Mauler Chainblade. Not technically an Eviscerator but I wanted to include it because it’s a very chunky 2 handed chain weapon, and older preacher models use a similar type of grip on their Eviscerators.
Last one probably isn’t perfectly applicable, but I still wanted to include a Khornate Bezerker with Eviscerator to showcase how gargantuan they can really be. While a different pattern for Space Marine use, the blade is still massive and about 3/4s the size of the Bezerker.
You could include older models such as Gabriel Seth but I only wanted to focus on the most recent models.