Examples of words for a 'person that makes things happen' are:
facilitator
leader
achiever
director
organizer
troublemaker
rabble-rouser
inventor
founder
creator
catalyst
ignite
initiate
to invent
Observe.
no. hopeful means that if you want something to happen, then you are hopeful that it will happen. pity means if something bad happened, it would be a pity.
Event and episode are synonyms for happening.
bale
sqw
Make changes
exhibit
fake
invent
bisect
Obviate
aggrevate