I played DK pretty solidly in v0.9a, but he had serious weaknesses. His recovery was far worse than it is now because from any sort of horizontal trajectory he had no room to mix it up: he just had to go as far as he good and pray that they would miss their punish. He had a tougher time than he even does now getting around projectiles and disjoints. His Punch, his main killing option, was worse. Notably, however, it's also the fact that the other characters were better at beating him. The Sora matchup was insane due to chaingrabs, the Jiggz matchup was a flurry of anything -> Rest to kill at 30%, the Sonic matchup was DK trying in vain to hit the swirling mass of Light Dashes and combos that would attack him, a lot of characters had serious chaingrabs and performable zero-deaths, and in general everyone just comboed him into oblivion. He had good range, a good chaingrab, and a decent grab overall, and decent kill power. Nothing else was really good.

your best option is to bait out the side special or other moves (since Ichigo has a bunch of end-lag on most of his moves) and then punish while he's in lag.
although, some punishes might feel like you have to act frame perfectly (a tiny bit of an exaggeration, but close enough)

EDIT: oops, forgot to mention that turnips and floating in general are insanely important in this MU
like, specifically floating at the right height for Side-special to pass underneath you and miss as you float toward Ichigo's departure point and then fade back toward his entry point (maybe waiting for an up-tilt if the player seems to be doing that frequently after side special), and then hitting with a b-air or n-air
or you can float higher than his up-tilt can reach, have a turnip with you, and drop it using the grab key and letting it hit Ichigo at his entry point (even if he up-tilts it, the turnip is still an active attackbox until it dies when it touches the floor, so it'll still be above him) you can use it as cover as you descend toward him and punish with an aerial.

People keep talking about end lag on Ichi's moves, but I defy anyone to tell me the punish window on side B>u tilt isn't tiny, especially factoring in the range of those moves. I can usually get in there with Sheik and tech chase to death, but with a floatier char I imagine it being extremely difficult.

Utilt is amazing. But a lot of his moves are laggy. Nair, bair, dair, uair, all smashes, ftilt, dtilt, neutral B, and side B to some extent are all punishable in ending lag or in starting lag. They aren't always punishable, but they aren't free either: all of these moves require some commitment.

I've been getting into side b matches a lot lately. Sometimes I win and sometimes I lose. They're actually decently fun though.

The attack I'm having most trouble against tho is his grounded Up B, specially with Jiggs. Since he has this wind effect there's no way for a short ranged fighter to punish this attack and has minimum lag too. In the Puff MU if Ichigo does this attack there's no other option but to reset to neutral, she has no options against it. Thouhgts?