You pull this out of your #7 cylinder...

[mklinker]

See attached... What do you think happened?

Not my LR4, but a friends RRS with the 5.0SC. Engine is seized, started pulling spark plugs, found this.

 

[Jeff Henderson]

Timing off? broken valve, hung up valve kept driving

 

[avslash]

That looks expensive.

 

[Quijote]

That looks expensive.

^This.

 

[BrandonM7]

Lean condition with boost cooked a piston apart and banged into ****, or timing came apart letting some valves meet pistons and then lots of stuff banged around. Either way it's a goner when a plug looks like that. Heads and block might be salvageable with machining, but it's likely cheaper to just replace all of it with a used complete engine. Even the supercharger probably got chewed up with debris when the engine started locking up and it sucked chunks back into itself.