Astro elevates the crowd at KCON on Sunday.Hours before America was riveted by the eclipse on Monday morning, another star passed into L.A.&rsquo;s orbit on Sunday night. Or, rather, a whole bunch of them did.The South Korean pop-culture festival KCON is the year&rsquo;s most authoritative gathering of K-Pop luminaries, and the pure shimmering optimism of the festival has made the concert more welcome than ever.The weekend-long event drew a constellation of otherwise rarely seen acts to Staples Center. Sunday night&rsquo;s set had a mix of bass-rattling hip-hop from NCT 127, high gloss boy-band dance moves from Astro and GOT7, and, in a culture defined by youthful devotion, a cameo from one of K-Pop's most veteran acclaimed singers, Kim Tae Woo.&nbsp;Obviously, the mood is less than optimistic at the moment on the Korean peninsula. But if anything, K-Pop is the most reliable source for unfettered glee in pop music. It&rsquo;s a world where existential threats almost never intrude. For one night at Staples Center, the K-Pop faithful could block out any bad vibes and revel in devotion. &nbsp;K-Pop, once somewhat of an underground phenomenon in America, has now settled into an established, multicultural fan base in Los Angeles and across the country. KCON is its church, as the scene&rsquo;s top acts only occasionally embark on their own headlining tours here. When they do, the crowds come in force.Saturday&rsquo;s set was a bit more of a showcase for K-Pop&rsquo;s ascendant all-female groups --&nbsp;Cosmic Girls and Girl&rsquo;s Day,&nbsp;among them, alongside fixtures such as VIXX and members of Super Junior. On the fest-closing Sunday night, however, the boy bands took over and the mood was riotous.The young singer-rapper Heize had an insouciant stage presence, and her old-school soul singing and '90s-era rap vibes connected the hyper-digital K-Pop world to a more analog era, as did&nbsp;the mixed-gender group Kard's soulful, sassy modern pop.Wanna One&rsquo;s upbeat, EDM-inflected tracks&nbsp;meshed with Astro&rsquo;s cheeky, irresistibly fun productions. One of the best aspects of K-Pop is the fan-first attitude of the groups, and they made time for fun stunts such as mocking up T-shirts onstage and shooting them into the crowd.&nbsp;NCT 127 was a bit more severe and commanding;&nbsp;their squiggly, bass-heavy hip-hop added gravity to a generally fizzy night, and it was a welcome dose of hard knocks. Kim Tae Woo, of the classic boy band g.o.d., was the night&rsquo;s semi-surprise guest, and the KCON crowd was admirably eager for a backtrack into an older, less digitally saturated era of K-Pop.Got7 rounded out the night with a vibrant, genre-skipping culmination of the night&rsquo;s ear-splitting devotionals from the Staples crowd, offering a few hours when everything seemed right.