Complex sentence: Lab Rat, a tie-in comic for "Portal 2", Chell is put in stasis by Doug Rattmann after the events of "Portal", who is revealed to be responsible for Chell taking part in the tests.
Split into simpler sentences: Lab Rat, a tie-in comic for "Portal 2", Chell is put in stasis by Doug Rattmann after the events of "Portal". He is revealed to be responsible for Chell taking part in the tests.