What makes this such a difficult match up for Luigi is that aside from perfect shielding, Luigi will always get pushed back when shielding an attack. Aside from his Luigi Cyclone, Luigi does not have any true moves to help him get inside Ike's spacing. Ike's f-air and n-air both out range any of Luigi's attacks in the air or on the ground. On top of that, if Luigi does not perfect shield, then he is pushed back, practically ensuring that Ike does not have to necessarily space perfectly to stay safe.
Luigi's kill moves are difficult to get off on Ike due to the spacing issue. His jab to up+b and F-smash both require Luigi to be close, and as long as Ike plays safe, it's not gonna happen.
Finally, Ike possesses the ability to hinder each Luigi's off stage recovery. Ike can drop down and counter Luigi's missile or simply walk off f-air/spike him as well.
If there is anything Luigi has going for him in this match, it's that once he does get inside, Ike is easy combo material. Damage can rack up rather quickly, but that also becomes more difficult when Ike is already at a higher damage rate.
I'm sorry theboredone, but this write up you made on luigi is okay I guess. But this one thing just shows me you have no knowleadge of my character. Seriously Luigi can jab to fsmash? XD