The guard giants might look threatening but hey are apparently juts good people dedicated with their job. If they really had no interest in welcoming visitors in their kingdom, then Adrian's group would have already been killed the moment they showed up on their doorsteps.
What Adrian did not realize is that he is emanating an aura that is making the giants not as hostile. The effect of the Angel Slayer title that he has is giving him a base level of familiarity towards the giants. The one thing that the giants hate the most are the angels because they have persecuted them non-stop since their inception.
When the six-meter tall giant and the four-meter-tall giantess appeared, the first one that they noticed is Adrian. He radiated a familiar feeling especially towards the tallest giant. Adrian does not know but the tallest giant that came out of the gate actually has the same title as him which is Angel Slayer.
