55:45 MK.
This match is literally a guessing game. It would be even if MK couldn't dair camp, but it is pretty effective against Pikachu once MK is winning.
Up close the match goes as follows:
MK F-tilt/D-tilt > Pika Ground approach
Pika SH Dair OR T-jolt approach > F-tilt
MK Up-b > SH Dair and T-jolt approach (Up-b OOS)
Pika run shield > Up-b
MK Grab > Pika run shield
SH Dair > MK Grab
D-smash, Thunder, F-smash, and T-jolt from the top break Tornado. MK has enough mobility in tornado to avoid basically every one of those. I have D-smashed on reaction to Tornado, the MK waits till the D-smash ends, and then hits me. It is quite silly.
Pikachu legit CG starts at 16%. You can get 3 regrabs I believe. The 2 best options are nair (Preferred) and reverse U-tilt. Reverse U-tilt puts MK above you, and unless MK literally dairs out of it, you can follow up with uairs. However, if he dairs, you can punish it. It is really just a guessing game...
U-smash thunder will kill MK at 100% before U-smash, and U-tilt thunder at 110% before u-tilt. MK's F-smash will kill Pikachu at ~120%, and his D-smash will kill at ~135% (Backswing). Nair will kill at ~130%
If we are winning, camp T-jolts. However, don't spam them. MK is really REALLY good at punishing...read my thread
http://www.smashboards.com/showthread.php?t=284281 for more details on that. I don't feel like I need to go over it.
If MK is dair camping, try to find a pattern. If you can, punish with DJ Uairs to Nair. Or...you can predict his jump and thunder. I have hit Seibrik with thunder like that several times. It is pretty amazing. Um...there isn't really many other options besides that, unless you try to punish landing...but nado/dimensional cape makes that near impossible.