Regarding the Giant Tribe, Merlin and Luce did not need Eldo's introduction on them. They knew about the Giant Tribe very well. After all, the Giant Tribe was not considered a weak civilization. They were a relatively strong civilization that even the Spell Caster civilization needed to treat with caution.
That was because in the Giant Tribe, there was a terrible Titan Giant, the strongest being in the Giant Tribe. It could even be comparable to an Ultimate Arcane Wizard.
Powerful beings on the level of an Arcane Wizard could be considered the top being in countless civilizations in the millions of dimensions in the Void Zone. Thus, once a being the level of an Arcane Wizard was born, that civilization would be called a powerful civilization. They would no longer be a weak civilization, and bullied by other civilizations.
Although the Giant Tribe only had one Titan Giant, it was enough to rank them as a powerful civilization in the Void Zone!