It's not easy Christmas shopping for Magnus Bane. He's literally seen and done it all in his 300 years. So what do you get for the immortal warlock who has everything? We asked author Cassandra Clare and the cast of Freeform's (née ABC Family) upcoming series "Shadowhunters" what they would get the High Warlock of Brooklyn for the holidays -- and needless to say, it sparked a few heated debates.

Does Magnus love Chairman Meow more than he loves Alec? Would an all-powerful warlock use a cleaning service? And when it comes to the age-old boxers vs. briefs debate, is Magnus really more of a sexy thong kind of guy? One thing is for certain: Magnus Bane is about to have a Christmas he'll never forget.

Cassandra Clare suggested getting something for Magnus' true love, Chairman Meow.

"Other than a copy of 'Lady Midnight,' which I feel he would enjoy?" Clare told MTV News. "What Magnus likes is if you get presents for his cat, Chairman Meow. He's very invested in Chairman Meow, so I would probably get him a cat sweater. Maybe a Christmas cat sweater."

"He's also working on improving Alec's style, so if you got Alec a nice, Dolce & Gabbana scarf, I think he's be pretty happy with that."

Dominic Sherwood would get him something from Jace.

"I would probably get him my name on a plaque, so he doesn't get it wrong," Sherwood said. "Ever. Or maybe a backscratcher, or a head massager -- of course, that would ruin the hair."

Emmeraude Toubia would slip a sexy little something under Malec's tree.

"I would get him a sexy lingerie set," said Toubia. "Maybe a sexy pair of Santa boxers or a Santa thong. It's something he could show Alec during their sexy times."

Katherine McNamara's gift would probably not make Chairman Meow happy. At all.

"I would get Magnus a kitten, so that Chairman Meow would have a friend," McNamara said. But do we think Chairman Meow would react well to a new kitten? We think he prefers being Magnus' center of attention.

Matthew Daddario thought Magnus would be really into antiquities.

"I'd get him old things," Daddario said. "I get him antiquities." Little did Daddario know that this would spark a huge debate among the "Shadowhunters" cast.

"He already has those antiquities because he's 300 years old," Sherwood said, to which Daddario responded: "He has them because he likes them. So I would get him new ones."

However, Sherwood wasn't ready to let this one go. "But he had them when they were new," he said. "How do you get somebody new antiquities? He already had those antiquities when they were new in that era. Buying them when they're old would just be moronic."

Clearly, Sherwood does not spend his Sunday afternoons thrifting for ~ vintage ~ finds.

Alberto Rosende had a pretty good idea, actually.

"I would get Magnus a tapestry of himself and Chairman Meow," he said.

Isaiah Mustafa's idea also sparked some debate.

"I'd buy him a mani-pedi package," Mustafa said. "I would also hire a housekeeper for him because that mansion really needs to be cleaned." But then Toubia pointed out that "he can just go like this [snaps fingers] and everything is cleaned." To be fair, that Greenpoint loft probably does need a good scrubbing.

"But you need a housekeeper," Mustafa reasoned, before Sherwood jumped in with the best idea ever, "Even just one of those little robot vacuums."

When Toubia suggested a BB-8 vacuuming droid, Sherwood added, "A gold-plated BB-8! I actually want one of those. Magnus doesn't need anything."

Daddario then had another, less controversial, idea.

"Get him cable. The full package with HBO and everything. Maybe even a subscription to Netflix. I feel like Alec would enjoy that, too."

Finally, Harry Shum, Jr. settled for the most unnerving gift of all.

"I think fear of mortality for one day," the actor suggested. "I don't know if it's a happy Christmas gift, per se, but it's a gift into another world, and Magnus has always been intrigued by mortals."

"How would we do that? Would we kidnap Chairman Meow for a day?" Daddario suggested. "And watch him slowly unravel."

...Or how about some glitter? That seems like a pretty safe idea, guys.

Well, you know what they say: 'Tis the season for gift-giving and cat-napping! Merry Christmas (we hope) to our favorite High Warlock of Brooklyn.