your brother needs improvement, just like everyone needs improvement.
He wont learn anything if he doesnt join or read threads in this forum, its arguably one of the best sources for ddd knowledge, next to experience.
he seemed slow to react, like at 0:28 he could have shielded wizards foot
(now that i look at it, i think he tried an fsmash?)
fsmash is great, it has killer range & power, if you dont sweetspot it your opponent gets sent into the air, good for a follow up. he just needs to know not to spam this move & when to use it.
there was a lack of tilts, no Utilts at all, which could have ended the game earlier.
he used too many smashes, and used them at the wrong time. especially uSmash and fSmash. he also used upB way too much when not recovering, basically, tell your brother to register here and read the forums.