Jesse Williams is sharing his thoughts on Alex Karev's surprising Grey's Anatomy ending.

In last week's farewell episode to Justin Chambers, Alex -- one of the last original Grey's characters -- was sent off in stunning fashion when it was revealed that he had abruptly left his wife, Jo (Camilla Luddington), to reunite with his former flame and ex-wife, Izzie Stevens (Katherine Heigl), and raising their two 5-year-old twins, Alexis and Eli, on a horse farm in Kansas. The shocking wrap-up to Alex's 16-year run on the show left many fans stunned and prompted Ellen Pompeo to defend the divisive ending, calling it the "best send-off" for the character.

"It can't not reverberate. It's such an incredible, impactful character," Williams told ET on Wednesday in New York City while promoting his upcoming Broadway debut in Take Me Out on the aftermath of Alex's departure. "I've always said that’s always been one of my favorite characters."

Even with Chambers' time on Grey's over, his absence will be deeply felt for the foreseeable future, especially when it comes to Jo's storyline moving forward.

"[Justin's] been one of the sweetest and funniest guys on set with me and everyone, certainly not just me. He's a light and he's so unassuming and chill as a person. And that character is specific and rooted and motivated," the 38-year-old actor said. "Yeah, it's a big departure and it will impact all of us and impact the relationships that form and sever as a result, for sure."

As Grey's moves on from Chambers' exit, Williams looked ahead to another key relationship that's been heating up since the start of the season: Jackson's blossoming romance with Station 19 firefighter, Vic (Barrett Doss).

"There will be some answers before the end of the season for both shows. I think that that relationship is playing an important role for both of them because they're both coming out of two very different situations -- her losing her fiance [Ripley] and Jackson having this little bit of bumper cars with a couple of relationships since the love of his life left and the person he co-parents with [April]," Williams said. "So yeah, that's going to continue to play out."

"And I think Jackson is still admittedly -- speaking of knowing yourself and with this play, being honest with yourself -- Jackson doesn't quite have both feet on the ground," he noted. "I think he's not entirely available as much as he might want to be."

Speaking of April, Williams addressed a lingering question that's been on the back of fans' minds ever since Sarah Drewleft the show at the end of season 14. The actor expressed optimism that that part of Jackson's story -- the fact that he and April are parents to a young daughter, Harriet -- will still remain a crucial part of his character's identity moving forward, even though fans haven't seen much of her since.

"I hope so. We'll see. We'll certainly see Harriet again. I know that we shot with her," Williams revealed. "I think in general, fans need to keep in mind -- I know we love, and I'm one of them, loved Japril -- but we don't see kids very often on the show anyway. But you know, you've got 12 series regulars. You’ve got story to tell. Kids are not always the best device for that. So I would just remind our fans that it's not unique to Japril. Harriet is not being isolated in some way. We don't see most of the kids very often outside of a glimpse. But any connection... Sarah Drew is one of my favorite people in the world and that character and that relationship are everything to me, so I'm all for anything that connects to that in any way."

Grey's Anatomy airs Thursdays at 8 p.m. ET/PT on ABC.

Reporting by Stacy Lambe.

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