Whatever doubts fans might have had about Yugi's fighting prowess in Jump Force turned out to be true. It also turned out to be true that the creatures he summons will have plenty of fighting prowess, and will combine their attacks.
When Yugi was first announced for Jump Force, the first thought on everyone's mind was "how is he going to fight overpowered characters like Goku?". This thought process imediatelly spawned a theory that he would instead summon the likes of Dark Magician to do the fighting for him, and subsequent screenshots proved this to be true.
The trailer above proves that he pretty much takes up the coach role instead of duking it out directly, as we can see Yugi standing still while Dark Magician and Dark Magician Girl pull their shiny moves off. Speaking of which, you can see the duo slapping Frieza all over the place and even pulling off a combined attack on the poor would-be emperor of Universe 7.
Yugi will not simply take the form of a statue on the battlefield though, as the trailer also shows him gap closing rather quickly at 0:33 mark. Unfortunately, we didn't get to see any moves from Slifer the Sky Dragon, but he made a brief appearance. This happened as Yugi summoned him and the summon animation pretty much the only info we have on Slifer at the moment.
Considering that Yugi didn't get to summon Exodia, it's possible that Spike Chunsoft are staying away from the "out of bounds" points of characters' power, which is likely the reason why we don't get to see an Ultra Instinct Goku. With that in mind, the chances of Saitama making an appearance are becoming lower.
On top of that, Jump Force is also in part a of Shonen Jump maagazine's 50 year jubilee and One Punch Man is not a part of that family. Jump Force is set to release in February 2019, and we might see more fighter reveals up to that point.