Complex sentence: Trapped in an obelisk following the death of its former master, Gigelf Liqueur, Grospoliner was freed by Katsumi; doing so required Katsumi to give the sword some of her blood.
Split into simpler sentences: Trapped in an obelisk following the death of its former master, Gigelf Liqueur, Grospolina was freed by Katsumi. Freeing Grospolina required Katsumi to give the sword some of her blood.