Sated Udyr, Shyvanna and Yi got in a fight.

triple kill

Udyr stops Yi the moment he reappears from Alpha Strike, he melts pretty much instantly between Udyr's Tiger stance and Shyvana's Burnout, then Udyr and Shyvana end up in a long, drawn-out duel where she most likely uses her ultimate to run away alive.

Udyr kills them all and still doesn't gank bot lane.

Kidding, Shyvana would win. I just wanted to make that joke.

Yi is very player dependant, he would die immediately in open combat against the other 2, but he has abilities with which he can dodge abilities or negate most of the damage. He's the most mobile, so he can choose when he fights and runs.

Between Shyvanna and Udyr, I don't really know. I guess Udyr is stronger in a 1v1 fight, though.

sated devourer encourages people to build stupidly, so it's really hard to say.

How many items we talkin here?

There's no way the other 2 would stand a chance against 6 item Yi

Once Shyvana has sated, she can build straight tank. The other team would never be able to kill her.