Final answer:
The question asks for Sirius Black's last words in 'Order of the Phoenix' which aren't included in the provided text excerpts. His actual last words from the 'Harry Potter' series were a taunt to Bellatrix Lestrange during their duel.
Step-by-step explanation:
The question relates to the last words spoken by the character Sirius Black in the book Harry Potter and the Order of the Phoenix. However, the provided references do not contain the actual last words from Sirius as these excerpts are from other texts or represent different scenarios. Sirius's last recorded words during the battle at the Department of Mysteries, before he was struck by Bellatrix Lestrange's curse and fell through the veil, were, "Come on, you can do better than that!" The student's request seems to be aimed at finding this specific moment from the Harry Potter series written by J.K. Rowling.