Character profile: Luigi is known for his powerful juggling and decent KO power. As his brother, he got fireballs as a projectile. But their limited effectiveness (they travel slowly and cause low damage) conclusively makes Luigi a close-quarters combatant.
How he will be playing: Although lightweight, Luigi is much faster than Ike. He will use his “short hopped fireballs to tornado” or his sliding Dsmash (which can poke under your shield) for approaching. If the tornado or Dsmash connects, they will throw you up where he can juggle you. Missed Aethers, Fsmashes, QDs, and other laggy moves can be punished severely with Fire punch. He may also use Fire punch out of a jab combo or in the air for early kills.
How you can fight back: Spacing is the key. With spacing you can prevent Luigi from countering your moves and prevent Fire punch KOs. So make sure you hit your attacks with the tip at all times. Remember that his fireballs are only diversion and look out for his tornado, if you shield it, the ending lag is enough for you to grab him or (depending on the distance he travelled) hitting an Ftilt. He can only perform his sliding Dsmash while he is walking, so watch out for that too. Also, his recovery can only travel horizontally or vertically and gimping during his recovery moves execution is easy.
Statistical analysis
Survivability: Much lighter than Ike, Luigi can be knocked off stage by 70% and KO’ed by 100% (from the center of Final Destination, using Ftilts). As mentioned before, his recovery moves leave him very vulnerable.
KO potential: Luigi moves have decent knockback overall, but his finishers are Fsmash (which can be angled), Nair and Fire punch. Their reach is very limited and requires Luigi to pressure and chase his opponent. Luigi doesn’t exceed at gimping Ike, as attempting to interrupt Aether can potentially get him killed.
Combo potential: Good. Can hack up to 60% if the Ike hasn’t spaced himself appropriately and kill if chained successfully with one of his finishers. Remember to air dodge and DI away from Luigi after been thrown into the air.
Range: He has good range for a close-quarters combatant, as his limbs stretch dramatically during his attacks. Not in league with Ike though.
Maneuverability: Luigi has a very good aerial and ground acceleration, which are crucial for spacing himself for juggling or applying one of his finishers.
Final analysis
**** (four stars), or slight easy matchup. Play smart and you have the advantage here.
Counterpick stages: Stages with roof prevent the use of Fire punch and you from be killed until at least 120%.
Ok, I propose we creating a measure of dificulty for the matchups so we can put Ike in the Brawl matchup chart. Here is my system suggestion:
* (one star): Hard matchup
** (two stars): Slightly hard matchup
*** (three stars): Even matchup
**** (four stars): Slight advantage
***** (five stars): Easy matchup
Also, I will work on a more detailed matchup against Luigi and edit this post.