He just stands there, eyes wide under his mask as the man transforms... Holy crap, that is awesome!
"That is incredible like I've seen a lot of crazy stuff here but dude! It's like straight outta one of those shows... Uh, not Power Rangers or Sentai, geez the name escapes me for some reason but they had suits tons like yours dude! Heck, they even said henshin!"
His babble would be cut off by the fact that oh yeah, this is a match, isn't it? Ryoma's halfway across the field by the time Spidey has recalled this little fact, so the boy would simply do his best to dodge for the moment, blade scraping against his arm as he rushes away with his own inhuman speed.
"Right gotta focus, standard webbing for now."
The blade would do a bit, but this suit's clearly made of pretty stern stuff. As for the kid, he's quickly leaping up into the air and onto the roof, he'd aim his wrists down Ryoma and fire a pair of webs toward the man's weapon, aiming to rip it away from his foe's grasp with a quick tug of both hands. Of course, if he'd hit somewhere else the man would most likely just be carried up, or he could miss given the small target.
"Side note, the powers are in fact spider related, yes, but the webbing is just my handy work and not a superpower. Pretty neat stuff though!"