As far as needing up upgrade "anything" you pretty much need to upgrade everything.
CPU is to slow and only Dual Core
Ram to low 8gig standard for gaming rigs these days.
The HD 5450 was low end when it came out and even more so now. Plus with only 1gig VRam that is not really enough for most newer games anymore.
You might be able to play some of those games with a good GPU if the game was not to CPU bound but really for most it would be a big bottleneck. You did not list your PSU but my guess would be that it would not handle a GPU upgrade anyway.
Sorry I know that is not what you really wanted to hear but the truth is you need a complete system upgrade as there is not one thing that could be done to make it play those games very good at all it is just to outdated and would not be worth putting money into.