Don't know if there's ever been a battle like this, but here's my version of it if there has been...on one side of the moon you have the JLA...on the other some of it, Galactus' heralds...the fight takes place on and around the moon....and the teams are as follows...
I thought he only took down Silver Surfer because Morg beat Terrax then those robots overwhelmed Morg. I think Silver Surfer,Morg at full power and maybe terrax could have beat Tyrant. Also I believe the Heralds could beat JLA easy. Tyrant was not a Herald he was suppose to be a companion for Galactus.
Yeah, technically he's not a herald...but he was still created by Big G.
But even powered down, he took on a ton of people and beat the crap out of them. Jack of Hearts, Surfer, Glads, etc. (there were more, but I can't remember them all). He also stalemated Thanos, and Thanos looked in bad shape by the end of the fight. I don't have the scans myself, but they've been posted on the forum more than once.
In any case, he's easily the most powerful one here. And give him capable teammates and the JLA team is screwed.
LOL and Thanos was able to get to an orb of power that tyrant had. Otherwise he was schmoked.........................Heralds win and do so with tyrant fighting and the heralds serving him tea and fanning him