to command = the boy will command the clawed giants?

means: dreams up a world of clawed giants (for him) to command

Thanks.
But I still don't get you very well.
Does the boy serve as the commander of the giants?

He will command them (will order them around)

"commander" is a noun.

Thanks

Thanks

We would say that a military naval or police officer "serves* or acts as the (or a) commander" - the role is a formal, official one. It is an occupation; the officer is employed by the state. In fact many navies have a officer rank named "Commander". However the role of Max and the monsters is not that kind. He is able to command them but in an informal manner: they obey him because they cannot do otherwise; he created them in his imagination to obey him, not because they are of lower rank or official grade.