Ike killed a god.

Link has a huge arsenal of weapons. One of them just so happens to be an indestructable shield. As well as a magic sheild(Zelda has this in smash bros)

Shulk controls everything with the monado. Time being one of them. 

Shulk isn't included by the OP's rules. A shield only covers a distinct area, any fire outside of that protective zone wouldn't be blocked.

Nayru's love anyone?

Ness and Shulk are JRPG protagonists and their power levels are exactly as absurd as that suggests. Shulk is excluded for no apparent reason, so I'll tell you how this plays out.

The only match-ups that matter are Ness vs Kratos and Ness vs Zeus. Nobody aside from Ness on the Melee roster is even close to literal-God-tier, which Kratos and Zeus are. So while Ness is fighting one of them, the other is single-handedly defeating the entire cast of Melee. Ness finishes his fight, maybe he won, if so he gets to fight the other. And then it's over.

I think it's more interesting to take such OP characters away for a moment and look at really weird match-ups. What even is Mr. Game & Watch? How would he fare against a Big Daddy? What would Mewtwo vs Cole be like? That sounds awesome. Can I get some Samus vs Raiden? He'd probably cut her up, but it would be dope as hell. Would it be Kirby or Jigglypuff fighting Fat Princess?

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Could you please explain further? For Link at least he doesn't stand a chance against, well, guns.

I mean, Kirby is literally unkillable as is Super Sonic. Obviously Super Sonic requires the Chaos Emeralds, so let's rule him out.

... So how does Kratos kill Kirby? The only way Kirby's species can be stopped, by in-game lore, is for them to be imprisoned outside of the regular laws of their universe (see: Galacta Knight, who is obviously future Kirby). Better question, what power does Kirby get when he inevitably eats Kratos?