a career or vengeance so direful that London was shocked.
Examples of direful
direful
He is, without doubt, the worst Education Secretary we've had, and we've had some direful ones.
From the guardian.co.uk
The rain had stopped, but the clouds were low, gray, and direful.
From the npr.org
So schematic and mechanical in style and subject matter that it must be easy to teach by dull female A level teachers, which explains its direful long term presence on the syllabus.
From the guardian.co.uk
More examples
Awful: causing fear or dread or terror; "the awful war"; "an awful risk"; "dire news"; "a career or vengeance so direful that London was shocked"; "the dread presence of the headmaster"; "polio is no longer the dreaded disease it once was"; "a dreadful storm"; "a fearful howling"; "horrendous ...
(direfully) in a direful manner; "seeing himself trapped, he cried out direfully"