So what is your question?.. do you need advice on how to do this? or do you want someone to create this for you?
If you need to know how to do this to create yourself, there are many ways to achieve this, easiest option would be to add a Wall sweep in the walls type properties: https://knowledge.autodesk.com/support/revit-products/learn-explore/caas/CloudHelp/cloudhelp/2016/EN...
Or just google videos on how to create custom wall sweeps, there are quite alot of videos on this so you should find it easy enough 🙂
Alternatively, you could model in place a Sweep, using the top of the wall as the path and just sketch your flashing profile.
Hope this helps
Alisder Brown
Senior BIM Coordinator
Scotland, UK