(King's BIO HAZARD2 mythos)
Tǔ was part of a terrorist organization led by Leon's father. Ater the B.H.S.T.'s arrival on the island, the terrorists attacked a train station being used by the Joker, one of God's more zealous followers. With his thugs killed, they captured the man and kept him close by while they planned an attack on the B.H.S.T. compound.
They later moved out to a field overlooking the compound. Behind the Joker, they infected themselves with the G-Virus and transformed into powerful mutants, ready to create havoc in the city.