Complex sentence: The role of Kelly, played by Chris Sullivan, was actually 6 roles joined together by Tobe Hooper after he met Sullivan who was initially offered the role of a crew member before they decided that the role should be played by a female.
Split into simpler sentences: The role of Kelly, played by Chris Sullivan, was actually a composite character of six previous ones. This merger was initiated by Tobe Hooper after he met Sullivan, who was initially offered the role of a crew member before they decided that the role should be played by a female.