inevitable
certain
fated
fateful
indefeasible
ineluctable
ineludible
inevasible
inexorable
inflexible
irresistible
irrevocable
necessary
relentless
resistless
sure
sure as death
sure as fate
unavoidable
uncontrollable
undeflectable
unevadable
unpreventable
unstoppable
unyielding
appal
avoidable
direful
imminent
incontrovertible
invariable
overwhelm
unalterable
unbearable
unbelievable
undeniable
unknowable
unquestionable
unwelcome
capable
incapable