There's many in disguise. Some who are not and others who look dramatically different from their normal selves. It's a feeling he has like an itch in the back of the brain used to being capable of sensing so much more and now urging him to find out more- but also in observing the way certain people move or carry themselves.

Admittedly some are good at pretending to be what the illusions suggest. He doesn't try to pry too much if there's any oddities to notice. He has his own issues to hide.

The backpack won't be hindering him. And Elidibus is aware he should take his own advice about reaping the advantages of engaging in some of this sport even if it's just in practice. Understanding the limits of his far less powerful (even by standards of mortals on his world) body. He is observant and as Eda tries to get the ball past him, he is capable of pivoting on a heel and moving diagonally to intercept before it goes too far. Whatever physical limitations had him remaining on the sidelines don't seem to be in regard to his reflexes.

"You suggest you've never played before. Yet you are very adept at guiding the ball. Is there a similar sport where you are from?"

The ball is shot back while he's speaking. Can Eda talk and play at the same time?