Super Smash Brothers - Probably a repost, but this explains why Lucas isn't here anymore...

And this also explains why Fox fights with no items.

The moment plays over and over again in his mind.
A moment of carelessness, a lifetime of regret… for all involved.
That’s why he can never allow anyone to get close to him again…
Not anyone that he loves, for fear of what might happen…
He has to remain alone…
It has become his madness mantra…
“No items, Fox only, Final Destination! No items, Fox only, Final Destination!

No items,

Fox only,

Final Destination…"