I watched the Japanese version, I wonder if the dialogue is changed. It's been years since I watched it, but I remember the other characters talking about how he's been holding back all this time. Maybe I'm not remembering right. Either way, he wasn't immediately demolished in the tournament, so he did a pretty good job considering the ridiculous power all fighters were supposed to have.
They go out of their way to highlight that Roshi felt useless during all the Cell and Buu stuff so he'd been training on his own since then.
I can't remember how many times Vegeta pulled up to a fight, said something along the lines of "I'm the strongest Sayan, I will destroy you easily" and then he loses, every. time. It seemed to be a key part of the formula that even after all the training and leveling up, he could never defeat anyone. It happened with Frieza, androids, cell, fat Buu, etc. dude just kept doing his trash talk and then losing over and over and over.
Actually kind of forgot what a fun scene that is, but I just don't watch that movie often as I tend to go for Broly or Super Hero whenever I'm in a modern DB movie mood.
This was good for the feels to see tien actually doing something with an effect on the story, but isn't this the same form cell had when he was easily dealing with trunks and Vegeta? There was some suspension of disbelief needed to consider that tien could hold him at bay like this. Seems like it probably should have been trivial for cell to do a much more powerful energy blast and quickly overpower him instead of just ramming himself into tiens blast over and over.
Tri-Beam is the most powerful pound for pound attack in the franchise. The in-universe explanation for it is because it uses his actual life energy rather than just his fighting energy, so it's literally killing him and not just tiring him out every time he fires it. Tien has used it to punch well above his weight several times like when he destroyed Nappa's armor, beat down Cell, and deflected a blast from Buu with it.
Maybe it's like the others are too smart to use it, like Vegeta not bothering to use the bulked up SS form because he's aware of the significant speed disadvantage, whereas trunks uses it to poor results because he doesn't know better.
