Complex sentence: It is highly questionable whether Guan Yu actually wielded the Green Dragon or whether it was merely part of the myths surrounding him, valid historical text from his time period made no mention of him or anyone wielding a similar weapon.
Split into simpler sentences: It is highly questionable whether Guan Yu actually wielded the Green Dragon or whether it was merely part of the myths surrounding him. Valid historical texts from his time period made no mention of him or anyone wielding a similar weapon.