I couldn't finish 'em. Looks like this's gonna get complicated.
The Death Machine is a boss from Final Fantasy Crystal Chronicles: Echoes of Time. There are two of them, a silver one which shoots missiles, and a gold one which uses magic. Like the Dragon in Final Fantasy Crystal Chronicles: Ring of Fates you can ride them, but they will attack you with missiles if you do. Their underside is the weak spot.
To get to it, the player must make the machines hit themselves with bright lasers, and after the hit machine attacks, it will overheat. Repetitively hit the machine in this state to make it fall unconscious for a few seconds, revealing the weak spot. Rapid slashing with a sword or spear at the sides of the machines has a chance to make them fall over.
If the player cannot make the machines fire the lasers, they must place their allies in front of one machine and control the other. It must then be directed towards allies (and the other machine), and it will hopefully start charging. The player must then immediately jump off and call their allies to you.
The silver machine may shoot three kinds of missiles - one that inflicts Slow, one that inflicts Gravity and one that makes the player invisible unable to see.