Oblivion is what happens when any human dies. It is the cessation of brain function and the eventual disolusion of the body through decomposition or or force. It is difficult to pin down at what point a body no longer functions however there is agreement that once rigor mortis sets in a body cannot be recesitated. Until modern-resurrection methods are discovered (if ever) oblivion sets in. Since the "soul" is a creative human cobstructioninvented by various cultures, we can be fairly confident it doesn't exist. You aren't going to heaven nor will you reincarnate, join universal consciousness or exist in any form at all. Your existence is over. You are kaput. Its disappointing news for some...and welcome by those who realise eternal existence would be grotesque in any form.
When the brain dies so does conciousness. There is no conceivable way that conciousness may survive after brain death. Some superstitious people have various magical theories as to how conciousness might continue however they are all without evidence and totally bananas when viewed rationally.
What is left of you
The only thing left of you is the decomposition of your body if you haven't been created or destroyed by force. Amongst the first cells to decompose are cells of the nervous system as they rely on oxygen more than other cells. As the circulation system has stopped functioning these cells have very limited access to oxygen. Brain cells can die within three minutes of death. The brain if left in tact will break down in a form similar to some other organs. Through no concievable mechanism can consciousness survive when your brain is liquidised or rests in ashes.
Resucitation and oblivion
That humans can be legally dead for a few minutes and resucitate or more importantly if humans can be revived through some yet discovered technology (freezing the body for example) what does that say about the time between your death and resucitation? Is it eternal oblivion or is it more analogous to a computer when it is shut off with no activity at all? Eternal oblivion would suggest once it begins it is forever though it can be argued that only really happens once the brain is completely beyond any possible recessitation. Is it temporary oblivion in between?
It is common to think of oblivion as some shadowy existence or blackness or emptiness. This is a misconception of oblivion. Oblivion is nothing. It cannot be black or empty because it's a lack of anything. It is no different to before you were born. There was absolutely nothing of you, nowhere in any way. The same is for death. It is non-existence.
Decomposition of the body
The human body will decompose over a period ranging from days to centuries depending on how well the body is shielded from humidity, wind, water and organic life. A body may be preserved through mumification, freezing, embalming or other natural and unatural preservation. It is currently beyond our technology to preserve and recesiate a body that has undergone rigormortis and or brain death.
Eventually all organic life will decompose and the matter that once made up the body will disperse into soil, air, bodies of water as well as beyond earth's atmosphere. It should be noted that human bodies are always shedding mater and that such shedded mater is effectively no different to the matter that disperses after decomposition. A human typically sheds skin cells equal to twice their body mass over a life span of seventy years.
Once the body has fully decomposed a person can be considered totally obliterated (both consciousness at brain death and later the body). All that remains are footprints (physical and recorded) and memories in living people. Foot prints should not be thought of as a substitute for you, they are just footprints, memories, feelings in others and objects that remind others of you and what you did. Eventually these will also disappears until absolutely nothing is left of a person. It is very unlikely that records of human existence can survive beyond a galactic catastrophic events meaning eventually humanity much like an individual human will be obliterated also, which would be an altogether different kind of oblivion.