I don’t believe that there have been enough emblems in the game to do this.
I know the top top top tier players are ONLY JUST getting enough to do +20 across a suite of heroes now… let alone being able to also have gone +20 on 3* heroes etc… too.
The ROI (Return on Investment) is actually quite poor really if you look at the maths.
- Top 1% in the 3* tournaments nets you, what on average 20-30 emblems every 3* tournament.
- 3* tournaments are appearing only 27% of the time based on this summary by Zephyr.
- A 3* hero costs 233 emblems to take to +20.
So if you had a full set of heroes (lets say 1 per class) you would need 93x 3 tournaments to pass which equates to 346 weeks to “earn your emblems back” (6.63 years)*
But that is just looking at the “Emblem earn back”, not including the other stuff you COULD get… But then really, the only two things of value from the Tournament Loot are the Ascension Materials & Emblems.
Events are another thing altogether… Top 100 in the events is less about having +20 heroes and more about re-running the stages over & over & over until you get a perfect opening board then blasting thru it in sub 40 seconds…
Edit to answer this:
Personally I would take Nodri to +20 if you don’t have Frida or King Arthur 
he will help out your vs. Red Titan scores very much indeed.