This study introduces a circular bio-manufacturing workflow utilizing biochar derived from spent mushroom substrates (SMS) of Pleurotus ostreatus and Pholiota adiposa. By reintegrating “myco-char” (fungal-sourced biochar) into the mycelium matrix, the resulting composites exhibit significant improvements in structural and thermal performance while simultaneously sequestering carbon and valorizing waste streams. Our preliminary results show up to a 15% increase in compressive strength and 10-15% enhancement in thermal stability compared to proprietary solid state fermentation data sets of hardwood and agricultural by-product substrate components without biochar, along with faster colonization rates by 4-6 days and increased mushroom fruit body yields by up to 25%. These initial results support theses of scalability and competitive commercialization of both biochar-enhanced mycelium composites and mushroom cultivation across a multitude of market segments, offering closed loop bio-manufacturing modi operandi for sustainable production. Compressive strength values for these composites are estimated between 1.4 and 2.1 MPa, surpassing conventional mycelium substrates with lower structural integrity. This added strength enables potential applications in construction, packaging, and other fields requiring lightweight, durable materials. Thermal conductivity measurements are projected to be as low as 0.03 to 0.08 W/m·K, providing insulation properties comparable to traditional materials. Additionally, biochar can be tuned to exhibit hydrophilic or hydrophobic properties, enhancing moisture regulation and durability across fluctuating environmental conditions. Beyond structural applications, the SMS used in this workflow, comprising approximately 15-20% hardwood pellets, results in a biochar that shares pretreated similarities with lignin-based activated carbons. This composition allows the biochar to develop a microporous-mesoporous structure through controlled pyrolysis and KOH activation, enhancing its electrochemical properties and surface area, which is ideal for energy storage and supercapacitor applications. Early tests suggest that myco-char, when incorporated into supercapacitor paste, achieves energy density values between 100 and 150 F/g. In other words, when myco-char is transformed into activated carbon this enables rapid energy charge and discharge without performance loss, making them strong candidates for emergency energy storage solutions, where swift and reliable energy access is essential. Such capabilities fabricated with emerging mycelium composite material components are relevant for organizations like the Federal Emergency Management Agency (FEMA), which prioritizes resilient infrastructure in disaster response scenarios. Equally as important to bolstering national security, this bio-manufacturing workflow also maximizes climate change mitigation efficiencies with in situ pyrolysis of SMS biomass. The proposed in situ process minimizes the carbon footprint and expunges the logistical, processing, and repurchasing costs otherwise incurred, creating a closed-loop system that reintegrates biochar directly back into cultivation and production cycles. In addition to energy storage and structural applications, this workflow incorporates advanced digital fabrication techniques, including subtractive and additive methods like hot wire cutting and 3D printing, and digitally assisted precision molding. These methods allow for customization, scalability, and product quality assurance ensuring the composites can be standardized for various industrial demands. This bio-manufacturing model provides a sustainable, circular solution to optimize supply chains, bridging the imperative to reduce and valorize waste streams and mitigate against the compounding risk of environmental collapse. As ongoing research explores scaling biochar-enhanced mycelium composites for energy-storing architectural elements, this work represents a significant advance in bio-manufacturing, expanding the boundaries of material science to realize multifunctional, sustainable applications for future generations.