I just pulled CapIW for the first time at 5*

I was pretty set on Mr. Fantastic being my next R4/R5 and use my R4 Science Rankup on him but now I'm not so sure...
• No Science Gem
I desperately need science help for my rosterShould I focus Cap? Or is Mr. Fantastic a viable option? -- who would be my best option(s) going into 6.2/Variants and on?