Oh!
Since I can't ever use these again I should share them with everyone...
During the last tourney I had very little time to plan my amalgam (I filled in midway through drafting for Quick Freeze) and just for fun, by the end of the tournament, I had made some amazing combos...here's a few.
1. Juggernaut, Flash, Green Lantern. Similar to what Scoob did, but with added durability from Juggs. Plus you could use Flash's mind (since you don't have to operate anything like Scoob had with Mjolnir) and any Flash is familiar with a GL ring. Thousands of punches and GL constructs within a few seconds, and very few would withstand that sort of barrage.
2. Mr. Majestic, Magneto, Metamorph - Stay with me here...this gets complex. Majestic, using his microscopic vision, sees that his body has some unique propeties...he fiddles with it and finds he can change his molecular structure. I'm not sure how he would figure out how to use Mag's powers but assuming he did somehow (he's a smart guy)...Metamorph can break his body into smaller chunks. Turn his body into a dense metal, then break the body up into thousands of shards, and control them with Mags powers. You now have thousands of uber-tough metal spikes capable of each hitting with Mr. Majestic punches. And to lose, each of the spikes (all acting independently) would need to be destroyed. Fun stuff.
3. Plastic Man, Phyla-Vell, Surfer - Plastic Man is basically immune to normal physical attacks. Enraged Hulk punches would amuse him. His weakness is energy. Phyla-Vell (briefly "Captain Marvel" when Genis lost the title), can absorb energy on a cosmic level and re-direct it (someone like Bishop would work fine for this too). In those 2, you essentially have a person who's hella-hard to kill using any means (I'm sure some magic-users could figure it out, but it would still be tough). Surfer is just to provide some offensive firepower and to be fast enough to hopefully negate the Flash-types in the tourney.
I had more, but those are the coolest I came up with.
Speaking of which, this sort of "I figured out how to make a guy who is unkillable," is why I would encourage that if there's another tournament, that it isn't amalgam anymore. I'm sure others can do much better than those I came up with, but those give you an idea.
-DM