EXCLUSIVE: Stephen Amell Dishes on 'TMNT 2', Olicity and Why Being a Dad is His Favorite Role Yet 

Playing EXCLUSIVE: Stephen Amell Dishes on 'TMNT 2', Olicity and Why Being a Dad is His Favorite Role Yet

, but at home with his wife, Cassandra Jean, and their 2-year-old daughter, Mavi, he's just Dad.

"It gets better by the day, 'cause [Mavi] gets smarter by the day," Amell gushed to ET at Los Angeles WonderCon over the weekend. "I know that every parent thinks that their daughter is a genius, but my daughter is a genius. Like, linguistically, she's very advanced, and so she's saying stuff to me now on a daily basis [that] I shake my head at. I don't know where she comes up with it."

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The 34-year-old actor, who frequently posts super cute daddy-daughter shots on Instagram, says that being a father is "for sure" his favorite role yet.

"She got out to our place -- we got a place out in Palm Springs -- and she climbed up on the bed and laid her head down and she goes, 'Oh, so nice to lay my head down. Think I need some time to myself,'" Amell shared with a smile. "I don't even know what that means."

Working on a Saturday Made Easier, by Maverick Amell.

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star trades in his more traditional superhero gear for Casey Jones' makeshift sports apparel-inspired armor in this summer's

sequel, and the actor spilled some details on the fan favorite character's debut in the Michael Bay

"He's trying to find himself," Amell explained, adding that his character is "excellent on rollerblades." "He's a corrections officer when we meet him in the movie, and it's not working out well for him, so he's trying to out some alternative methods."

Stephen Amell as Casey Jones https://t.co/3EszI6nT26 #TMNT2 pic.twitter.com/IQmHR7s5j8

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The actor also shared some teases for the upcoming end of

fourth season, which fans already know is leading to the death of someone close to Amell's Oliver Queen/Green Arrow character.

"We have to solve what we've been working on the entire year, which is that someone important to us is in the grave," he shared, noting that fans will find out which character is meeting a fated end "relatively soon."

As for the CW show's other heartbreaking storyline -- the recent breakup of Oliver and Felicity (Emily Bett Rickards) -- Amell had less certainty.

"Who's to say?" he answered coyly, when asked if "Olicity" fans will be pleased with the end of the season. "I don't know."

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