Valhalla is the Norse afterworld only open to those who die fighting in war. There is a huge mead (honey beer) hall there, centered by a huge banquet table with endless food and drink. The gods will be there to drink with you! This song is the sort used to build energy and fury before entering battle. They look off shore and see several warships approaching - they will clearly be outnumbered, but they will stand and fight. Valhalla is calling.
Valhalla is the Viking version of heaven, where those who died in battle were supposed to end up. Hence all the lyrics about fighting and war. As mentioned below, J.None was a full member of Voiceplay until 2021 when he left to sing with the US Navy music section. He comes back when on leave from his duties, to join his friends again. In his navy dutes he currently sings bass but has a wide range , as can be heard in their latest release, The Lion Sleeps Tonight. Geoff, Layne and Eli all have a wide range though Geoff's bass is the lowest, and Cesar can hit some very high notes too.
J staring out across the water at the beginning used to be a regular member of the group. He’s been away (in the US Navy) and now he’s come back (at least for this). The rap was added and some hints to his being in the military (ops, etc). I just love that while he’s rapping in the background you can hear the guys singing “This is WAR”. It always gives me chills. Previously they did a cover of My Mother Told Me (also associated with the video game Assassin’s Creed and the TV program The Vikings). J was still a permanent member of the group then. The makeup and a lot of the costuming is from MMTM. Among their tattoos are runes spelling out VoicePlay. Cesar was not yet a member of the group. Jose Rosario Jr was the guest artist. Cesar is wearing the same robe that Jose wore in My Mother Told Me. Layne (beatboxer ) did the arrangement and Eli (bald rock god) the amazing backgrounds using Unreal Engine which is used in filmmaking and video games to provide digital backgrounds. The only real pieces in that set are the tables and benches. Even the door that J walks through was pure CGI. He was standing in front of the screens and the background opened for him. Layne was responsible for the creaking door sound.. It was filmed, not green screen, but at a studio with immense (Full wall!) LED screens.
This is the second Viking song they have done. The first was" My Mother Told Me" think it was inspired by a TV show. Doesn't matter I love all their stuff. If you haven't you should check out the bass Geoff Castelluccis' channel where he does his own LOW Bass covers.