WCW had one goal when they brought in the Ultimate Warrior, and that was to play to all of his weaknesses. The Ultimate Warrior was never very good at speaking.
The WWE did their best to hide this weakness by only letting him do backstage promos for 30 second stretches where he could just be super energetic without having to actually make sense in anything that he said.
Of course, WCW gave him live promos where he was forced to give long, drawn out speeches. Ultimate Warrior's schtick worked best in quick bursts of nonsense, long diatribes of nonsense only worked great at killing a crowd. So his debut definitely involved Warrior going on for twenty minutes where he accused Hulk Hogan of shitting his pants. Grade A work.
Ultimate Warrior wasn't really a wrestler, at least not a competent one; he was a body. The WWE displayed that body, and even though the Warrior had lost some size later on in his career, he was still jacked by any measurement. Still, the WCW put him in jeans, a duster, and wrestling boots. Ultimate Warrior's greatest attribute as a professional wrestler was just looking like The Ultimate Warrior. WCW decided to cover him up.
Finally, Ultimate Warrior had one of the best entrances in pro wrestling history. They gave him metal music and had him sprint down to the ring. Instead they made this his theme, and gave him a trap door to rise into the ring from. So instead of sprinting in, kicking ass, and sprinting out, he came through a trap door and escaped through a trap door like a coward. Ultimate Warrior should never be using nefarious ways to escape; he should be clotheslining his way out of every situation. In fact, that is how WCW should have brought him back. Just send him to every day activities, and have him clothesline his way through DMV lines, body press a car to change a tire, and give a big splash to a tarantula. That would have been awesome.
He only had three matches, and only one singles match. We'll start there with the most overbooked match in wrestling history, Hogan vs. Warrior II, Electric Boogaloo. It was two wrestlers who were well past their prime, who were never known for their in-ring work, and they tried to recreate magic from nearly a decade earlier. It did not go well. There was the flame paper that Hogan tried to throw at Warrior, and that, uh, didn't come close to working properly. Then, Hogan won the match with help from Horace, who had just left the flock to be outed as Hogan's nephew. Honestly, by that point, I think everyone in the crowd was just happy it was over.
The second match Warrior had actually could have been cool as he tagged with his old tag partner, Sting, to take on Bret Hart and Hulk Hogan. I say it could have been cool had they actually had four of the most popular professional wrestlers in history just have a match, because by just having those guys out there, the crowd would have been way into it. Instead, they managed to put on one of the worst tag matches ever. Sting got beat up for five minutes, finally made the tag to Warrior, who never took off his stupid airbrushed duster jacket and cleaned house until the nWo interfered a minute later. Then Warrior filled the ring with smoke so he could escape.
His final match was a 3 on 3 on 3 match where he was on Team WCW with Roddy Piper and DDP to take on Team nWo Black and White with Hogan, Bret Hart, and Stevie Ray, and nWo Wolfpack with Kevin Nash, Lex Luger, and Sting. Yes, Sting, the ultimate WCW guy, was in that weird stage where he just up and decided he was no longer brooding, and wore red face paint. It was a 25 minute match, and Warrior was out there for three minutes, but they at least finally let him run down to the ring, and the crowd went crazy for it. He also tore apart the cage to get to Hogan, which would eventually lead to...nothing. Warrior was never seen or heard from again.
Ultimate Warrior's run in WCW was one giant missed opportunity. You were never going to recreate the magic of WrestleMania VI, but they could have still done some really fun things with him. Instead, they played to his weaknesses and let that initial excitement turn to apathy. It was almost a relief when Warrior disappeared, especially since he didn't need a trap door to do it.