From my techniques thread:
Ike is actually one of Bowser's better match-ups, since it's my opinion that Bowser is actually an Ike-counter: the majority of Ike's moves are so slow that Bowser should have no problem dodging them and Ike's moves which will kill other characters at low percentages will not kill Bowser. Also, Ike's sword strokes are immediately shut down by Bowser's fire breath, meaning it's possible to catch Ike in a PoF mid-swing. Also, Ike's toward-B is immediately shut down by Bowser's fire.
-If he starts charging his toward+B, you have him over a barrel. Either start your fire breath or shield when he releases and charges you, block the hit then rush him and Toward+B. Either way, he's very punishable and this seems to be the preferred method of approach for most Ike players.
-For the love of god, STAY ON YOUR TOES! Be ready to dodge in a split second. Jump and act as if you're about to move in, then 2nd jump back the other way. This can fool many Ike players into swinging and leaving an opening for a Fair by Bowser.
-Do NOT use Bowser's Bair unless you're high enough off the ground that you will not experience landing lag and avoid using his Dair at all. Also, don't Bowser bomb unless you know for certain that you've mindgamed your opponent enough to know they'll fall for it. Also, avoid using smash attacks without certainty and ALWAYS fortress AWAY from Ike.
-Most matchups are better played if Bowser is waiting for an opponent to screw up so he can punish. In this case, the roles are reversed, as Ike is waiting for YOU to screw up so he can punish, and punish he will.
-Ike's running A move actually causes him to lunge closer to you as he swings his sword. If you can shield and block it, you're typically in range for either a grab or a Toward+B.
-Ike has three moves which come out quickly: his Bair, his neutral A combo and his Up+B, and only the Bair can really kill Bowser. If he uses his Up+B and you can get behind him, do so: you'll have a golden opportunity to punish with a smash attack upon him landing. Otherwise, avoid it, as getting caught in it will damage you. His Utilt can also be dangerous, but only because the hitbox starts as soon as the move begins.
-If Ike is facing away from you, it's either because he's lagging or he intends to shorthop and Bair you, which comes out very fast and can kill. Beware the backwards Ike.
-Avoid being on a platform above Ike. His Up smash takes a long time to come out and is likewise obscenely powerful. Always DI through platforms and be on the ground whenever possible and use your air dodge to get back to the ground.
-KOing Ike is best done with ftilts to get him over the edge, then follow it up with a flame tickle to keep him off the stage. The flame tickle will force him to restart his Up+B 2-3 times and each time he always seems to be pushed further under the stage because of it. After the 3rd time, his sword will generally come up through the stage and he'll miss the edge grab on the way down. Quickly timed Fairs can also catch Ike players off guard, but Ike's Fair is very powerful and has good range and outranks Bowser's priority.
-Some Ike players will use the Toward+B in mid-air when recovering to get to a higher platform if they're recovering from higher up. Watch how your Ike player behaves and counter accordingly. You can even stand near the ledge in an attempt to trick Ike into trying to get over you, then quickly move back and punish with either a Toward+B grab or a Uair if he lands on a platform above you. Ike will need to start charging his Toward+B early if he hopes to get enough distance and you should be able to react accordingly.
-Do not attempt to PoF ledgeguard Ike. You will get caught in his Up+B and punished. However, if you stand on the edge and shield as Ike attacks up from the ledge, you do have a prime chance to Dtilt for a KO if Ike is sufficiently damaged.
-When returning to the ledge, come back low, fortress to the ledge for an immediate grab and jump so you'll clear a ledge-guarding Ike.
-If Ike starts charging his Neutral+B and you can get behind him, do so. However, avoid approaching him from the front at all costs: as he releases the move, not only does he create a large explosion in front of him, but he also has super armor during the execution.
In summary, fight Ike as if you're a middleweight fighting a heavyweight, even though you're the heaviest character in the game. Grab him whenever you can with shield grabs and catch him in PoFs as often as possible. Despite his power, Ike is much lighter than you but must be treated with extreme caution. His attacks are slow, but still fast enough to punish Bowser's laggier moves.
Hi upB hs no range outside the thrown-up sword, so yeah, just space.
