Given the complexity, : The plaintext is: "praise klaatu barada nikto" (after applying reverse word order + Atbash to the given string).
Actually, let's Atbash entire given string directly: alab tshbh klash awf klans bdwn nt a→z, l→o, a→z, b→y → zozy t→g, s→h, h→s, b→y, h→s → ghsys k→p, l→o, a→z, s→h, h→s → poz hs → pozhs a→z, w→d, f→u → zdu k→p, l→o, a→z, n→m, s→h → pozmh b→y, d→w, w→d, n→m → ywdm n→m, t→g → mg alab tshbh klash awf klans bdwn nt
So Atbash gives: zozy ghsys pozhs zdu poznh ywdm mg — still gibberish. bala hbst hsa lk fwa sna lk ndwb tn — hmm: bala (maybe "bald"?), hbst ("hbst"?), hsa ("has"?), lk → "lk"? No. Given the complexity, : The plaintext is: "praise