The following are the meanings listed in the dictionary against the phrase ‘take on’. In which meaning is it used in the third paragraph of the account:

take on sth: to begin to have a particular quality or appearance; to assume sth

take sb on: to employ sb; to engage sb to accept sb as one’s opponent in a game, contest or conflict

take sb/sth on: to decide to do sth; to allow sth/sb to enter e.g. a bus, plane or ship; to take sth/sb on board