Little has been seen or heard from CW Seed's Constantine animated series since it was first announced -- but series star Matt Ryan, who makes a guest appearance on DC's Legends of Tomorrow as Constantine tonight, says that his voice work is almost complete, and will be finished in soon.

The series will mark Ryan's third story in the Arrowverse -- the colloquial name for the universe shared by Supergirl, The Flash, Legends, and Arrow. Constantine appeared in a season four episode of Arrow, which is referenced when he comes to Legends tonight.

"I have done the animated series -- I did that last year sometime, I think," Ryan told ComicBook.com. "It feels like a long time ago. I actually have to go in in the next couple weeks to do another session to finish it off."

Ryan told us he has little trouble shaking the rust off -- even with long breaks between outings as Constantine, he feels connected to the character, and as long as the material is good he slips right back into it.

"It was great," he said. "It was a fantastic script and that was the first time I played him since, I think Justice League Dark animation, and obviously, it's very different kind of playing him with a voice and actually playing the character in the live action as well, but it's a great script and I'm looking forward to seeing it."

Fans of Ryan's own series will likely enjoy tonight's episode, which feels more like an episode of Constantine than the character's previous role on Arrow did, without losing Legends' own unique identity.

“It did feel like a Constantine episode in a way,” Ryan said. “Getting to do the exorcisms again is great because in the Arrow episode there’s only a little bit of the spells anythings, and there was quite a bit of that [in Legends] and it did feel like he was driving the episode. It was surprisingly darker than I thought it was going to be, which was great. I thought the tone of it was quite dark compared to what I’ve seen of previous episodes. I thought that was great, and that Constantine fitted right into that.”

Constantine's own background, both from the comics and from Ryan's short-lived NBC series, will inform the episode, as well, which may give fans some ideas about what CW Seed's Constantine animated series might hold when it debuts later this year.

DC's Legends of Tomorrow airs on Monday nights at 8 p.m. ET/PT on The CW, beginning tonight and running through April, when the season concludes and Supergirl returns to take over the time slot.