Giant Fierce Diety Link doesn't exist, because Link never wears, and wouldn't wear, 2 masks at once. He can't activate both at once, anyway.
I can imagine Link charging Samus, and Samus just knocking him away. Then she'd turn to assess the ship damage, and a boomerang hits her in the helmet. She turns around to see Link with a mask in one hand and the boomerang flying into the other. He swiftly places the mask on, and transforms into Goron Link. Samus fires multiple rounds of fire shots at him, but since fire has no effect on a Goron, as they can walk through lava, Goron Link rolls through the shots, unseen by Samus as Link is covered in the fire shots, and rams Samus with spikes out, sending Samus flying back 6-8 feet. He runs toward Samus, but just sees a little ball, and a couple other smaller ones. (Samus and her bombs) They explode, knocking Link back a farther distance than what Samus went through, and Link catches himself. Seeing Samus in Ball form, and now understanding that it's her, Link rips off his Goron Mask and whips out his hookshot. He grabs Samus in midair, and pulls her toward himself, readying his Megaton Hammer. WHAM!! Straight down into the ground, Samus goes, about half a foot. No apparent damage is done to Samus's ball form. Samus gets up, in regular form, and aims her arm cannon straight at Link. Link pulls out his Hylian Shield, and it takes the shot, but no more shield... While managing to take the shot, it also broke into a kajillion pieces. Link flew back 10 feet. Samus approaches Link slowly, readying another missle. Link is on the ground, in pain. She aims at Link, and Link touches both hands to the ground. Samus fires, but a powerful wave of Din's Fire pushes the missle back, and forces samus back quite a distance, too. She uses her Grappling Beam to grab Link, she pulls him toward her, she holds him up in the air, and she looks him in the face. The Blast Mask is on Link's face. Link laughs, as he explodes, sending them both flying in opposite directions. Samus gets up, runs over to Link (with that awesome glowing super-fast run attack that she does in Super Metroid). After the blast, though, Link was charging his sword. When Samus hit him, he unleashed it, sending her flying 90 degrees off, sraight into a mountain. With no time to slow down, she crashes into it. Samus goes into ball form so that she can fit out of the crater she left in the mountain, comes out of ball mode, grapples Link again, throws him up in the air, and screw attacks him over and over. When she can sense that Link is finally dead, she stops, and walks toward the ship. A fairy quietly flys out of a bottle that Link had, bringing him back to life. He stands up, and puts on the Giant Mask. He screams as he transforms, and Samus hears him. She turns around to see Link growing at an alarming rate. She does the cool running attack again, to get to Link fast. Link swings his sword at her, but she dodges. She grapples his sword, pulling herself up onto his head. She goes into ball mode, rolls between the mask and his face, and drops a super bomb. She then jumps down, still dodging Link's sword. The bomb goes off, separating Link from his mask. The mask is destroyed. Samus charges up a big shot from her cannon and holds it. (like in melee) Link casts Naryu's Love. They face each other.
lol, not really part of a debate, as I alone made it up, but doesn't that sound cool???