I am so glad to hear OTHER people bringing up Arthemis. They are the band that got me looking at European music acts after NOT listening to new music for...12+ years.
Heroes is a fun album - different sound likely due to 2 factors: Lead guitarist Andy's writing style changing over the years; and a COMPLETE change in the lineup, other than Andy. Alessio Garavello was former singer, he now has his own project in England (A New Tomorrow). Al's voice has a super crazy range, but is not growly and gruff. I think his voice did not match the new direction of Andy's music in Black Society (A really great album, their first edgy/metally work, less Power metally). New vocalist Fabio has a rougher edged voice, more appropriate (imo) to the lyrics and musical style.
Arthemis definitely has two periods: the "The Damned Ship/Golden Dawn/Back From the Heat" phase, and the newer "Black Society/Heroes" phase. Their first three full length albums were Power Metal to the core, mythological/fantasy/sci-fi based themes, soaring arrangements, and Al's amazing range of vocals. "Back from the Heat" was their best in this genre, and the 1st & last tracks were great. The shred solo on track 3 (Free Spirit) is wicked fast, wicked good.
"Black Society" is a departure from that, and you can almost tell the individual bands they take inspiration from on each song. Angels in Black is a great dark ballad, and was their first video. For good high speed head banging, I recommend listening to "Fright Train", "Electri-Fire", and "Mr. Evil."
"Heroes" not only has the new singer, but tighter musicians on Bass and Drums (again, imo). I don't have a favorite track yet, but my son's hands-down favorite is "Vortex" - catchy chorus, and he screamed it in the car before wrestling tournaments.
Since I do not travel to Italy often, and have never been to Ibiza or Japan, I have not seeen them live... dammit. Oh - Andy was also the lead guitarist for Power Quest on the 2 albums prior to the latest, along with Al being vocalist.
I'll shut up now.