A Phase 5 OCS civilisation operates kugelblitz computers — black holes formed from focused radiation, which evaporate via Hawking radiation and emit particles democratically across all Standard Model species. The neutrino channel is particularly valuable: neutrinos escape the IMBH accretion environment without absorption, unlike photons. Dvali & Osmanov (2023) showed that for kugelblitz with THawking >> 1 GeV, approximately 45% of total Hawking power is emitted as neutrinos. At M = 10&sup8; kg (Scenario A), TH ≈ 10¹⁵ K and total Hawking power ≈ 1.6×10¹⁴ W. At M = 10¹⁰ kg (Scenario B), TH ≈ 10¹³ K and Hawking power ≈ 1.6×10¹⁰ W — but the longer evaporation time of ~10&sup8; years makes it a viable persistent signal source.