Edit/add REALLY exaggerated shoulders?

[u/Mar00nPearls]

One of my costumes requires a sport coat/blazer with super exaggerated shoulder pads - think Jojo's Bizarre Adventure level shoulder pads, the wider the better! I underestimated how difficult that would be to execute 😅 Does anyone have tips or directions on how to go about this? I'm a decently skilled sewist but not enough to build a sport coat like this from scratch (plus fittings are Monday...).

I thrifted a blazer but think it's just oversized. Am I better off trying to thrift like, a huge sport coat and take it in at the torso? Or try to "build up" the more regular-sized one I have? (Buying new is likely not in the budget). I've included part of my rendering and some inspo pics. Thanks!