What is the best weapon

Hint 1 of 10:

Grenades are the most powerful, but they're heavy and hard to make.

Hint 2 of 10:

The modern rifle is very good, but only modern people can use one.

Hint 3 of 10:

You can find a modern rifle in the southern part of the spider cave.

Hint 4 of 10:

You can find a modern rifle in the old Piniro village.

Hint 5 of 10:

The Kotl black staff is extremely powerful against Myrmidex only.

Hint 6 of 10:

The obsidian sword is the best contact weapon.

Hint 7 of 10:

The boomerang, though weak,  is a range weapon that never runs out.