"I thought they'd tell me to stay a bit lighter, but it was nothing like that," the actor tells PEOPLE.
Credit: Everett

Fans of Smallville likely remember Alan Ritchson’s character Aquaman as a charming piece of eye candy who always bared his chest.

But Ritchson, 27, who returns Friday night to the long-running CW series, will come back much “darker” and “edgy.” The actor, who also stars on Spike’s Blue Mountain State, says the expected darkness of Aquaman’s revival much exceeds his own original expectations and will surprise viewers.

“It’s exciting to me,” Ritchson told PEOPLE. “I was waiting for [producers] to tell me to pull back a little and stay lighter like like the last four times around. But it was nothing like that. It’s getting gritty.”

Adds Ritchson, “Aquaman’s got the weight of these new responsibilities that he has as the new king, with his new wife, the queen. It’s this different side of him than I think has been seen in the past, so it was fun to play that.”

The decade-long series, which will conclude for good once this season ends, has a lot more in store before its finale.

“Loose ends tie up, and all this good stuff comes to fruition,” Ritchson says. “There’s so much to be done. Everyone’s so focused.”