Bloom Forge was the polar opposite of Necro Forge.
Instead of creating a perfect pseudo core from the start and merge it with its host, Lith would create a small pseudo core and the mana pathways necessary to prevent it from dissipating at the same time directly inside the hammer.
It was supposed to require less focus and mana compared to Necro Forge. The mana pathways would allow Lith's energy to mix with that of the mana crystals during the Forgemastering process.
It would reduce the resistance that the pseudo core experienced when interacting with the mana vessels, and by starting small, all mistakes Lith might make could be tweaked as he shaped the core. Bloom Forge was far from perfect, even in theory.
Lith had already predicted that the more the Forgemastering process progressed, the more difficult things would become. Neither the pseudo core nor the mana pathways could exceed their ideal form.