Lost Soul is listed as a technical death metal band on Metal Archives, but I'm not so sure that's accurate. Yes, their music is technical, but it's just as accurate to simply label them as what they are - a Polish death metal band. When I say "Polish death meal," what springs to mind? Probably Vader, maybe Hate, maybe mid-era Behemoth...precise, supercharged death metal that takes a little bit from Florida and Sweden. Early Lost Soul is predominantly blasty. 2000's Scream of the Mourning Star is an excellent debut, and it might as well be your starting point.
Personally, my favorite Lost Soul material can be found on 2005's Chaostream, which was their third long player if you're counting at home. It's marked by seismic riffs that hit without warning (see "Godstate" to hear what I'm talking about). Blastbeats are still excessive, but by this point, the band had found their inner groove. Melody be damned, a song like "Shameless Race" piledrives its way into your brain. 2009's Immerse in Infinity is sonically epic, and it actually served as my introduction to Lost Soul. Layers upon layers of lead guitars compete for your attention. "...If the Dead Can Speak" is a killer track that climaxes with an expansive solo. There are moments that could be confused for nu-metal, and they wouldn't work on any other album. But they work here.
I know I already said that Chaostream was my favorite of the bunch, but between you and me, it's a toss-up. Immerse in Infinity is just so massive. 2015 saw the release of Atlantis: The New Beginning, which currently stands as Lost Soul's final hour. It's definitely their weakest effort, as everything sounds too massive. It tries to be "high concept," but it collapses beneath chaotic guitar work and odd chanting. Don't let that deter you from checking out Lost Soul, though. Honestly, Chaostream is a sleeper pick, as it may be one of the strongest post-2000 death metal albums to come out of Central Europe. Yep.
I thought I would end up typing a novel's worth of panegyric praise, and I probably still could, but I'll cap it here for the sake of brevity and sanity. Lost Soul is listed as active, so maybe we'll get something new in the not-too-distant future? Question mark???