I still agree with 55:45 Pikachu.
Pikachu doesn't have a hard time getting in. With T-jolt approaches DK can't do much. His F-tilt won't hit the jolt and us, it will only hit one. If he shields it facing towards us, we can jump and T-jolt again. Once we get in we destroy obviously, with our pseudo combos and uair juggling. Don't forget the CG! Edgeguarding/perssuring will give DK a lot of %, so make sure you do it well.
On the other side, if DK is on the offensive...Pikachu runs for his life. T-jolts slow him down, but his bair is basically a platform with a hitbox. at like 15% it combos into itself and puts Pikachu in a bad position. Down-B will outrange anything you can try to do on the ground defensively (Including pivot F-smashes). However, DK is very predictable. If he is in the air facing away from you, shield. Watch for the FF landing to grab and the headbutt (Forward B). It can destroy shields.
Pikachu has actually a very little amount of pressure from DK compared to most characters. Most characters are forced to air-dodge when DK jumps at them when they are in the air, but Pikachu can QAC away. It alleviates a ton of pressure. Just don't do it too close or you will get hit and then have phantom lag.
Getting killed is obviously a big fear. We will die no later than 90% from any smash attack/punch. Fresh uair about halfway in the air on FD will kill at like...120-130%. Bair fresh will kill at 130% at the edge, and u-tilt will kill at 100%. It is stupidly strong for no reason...
Pikachu should get a lot of easy thunder kills. If we place it in the middle of him, he can't escape, he is too fat. U-smash thunder will kill at 120% before U-smash probably. U-tilt thunder at 140%. F-smash at the edge probably at like 130-140%. Remember...if he up-b breaks, free anything.
:D