Complex sentence: The Tekno-Crystals are fictional items within the series "Tekkaman Blade" and its american adaptation, "Teknoman", or the OVA "Tekkaman Blade II", however the ones used in the original series differ slightly to those used in the OVA.
Split into simpler sentences: The Tekno-Crystals are fictional items within the series "Tekkaman Blade" and its american adaptation, "Teknoman", or the OVA "Tekkaman Blade II". However the ones used in the original series differ slightly to those used in the OVA.