When to level 5 stars

I have a similar question. I've kept my 5* at 255, not just because they have only 1 cover, except OML, he's 1/2/0... but because I had no champ 4* yet.

I champed my first 4* yesterday, 4* Thor, so now that I have a level 271 character, I then have 255, 255, 255, 255, then the rest of my 4* are 220 HB, then 200 XFW, 200 XFDP, 200 Cyclops, 185 Carnage... then way lower from there.

With one character pushing ahead like that, is it safe to bring up my 5* to 270 (which the one cover allows) or will that hose my scaling? OML can go to 300 with those 3 covers... should I bring him to 270 as well?

This is the part of the game I've been anxious to get to finally, but now that i'm getting closer, I don't want to screw it all up by doing it wrong.

Here's my personal opinion on 5* leveling:

If you have no champed 4*s:

Do not level your 5*s unless you have OML and Phoenix or GG. In that case, I think you want at least 6 covers for OML including at least one of each color and 8 covers for Phoenix (skewed to purple/red) or GG. And then I would level both to OML's cover cap.

Less than that and I think you are setting your MMR up for facing teams that are much tougher than you want to face. And in PVE, Heroics will become even more impossible.

If you have a top tier 4* champed:

You can level OML, but I would hold off on the others unless it's an extremely well covered Phoenix (or maybe GG, I don't know how good he is). That said, I would still hold off on OML until you have 6 covers, preferably with at least 1 of each cover. At least 1 yellow is a must have.

If you have multiple top tier 4*s champed:

Same as above, but leveling the others a little bit won't hurt you as much. You could take them to 270-280 and not affect scaling or MMR at all, and probably higher because the likelihood of one of your 4*s being boosted isn't as low. That said, I wouldn't go much higher than 300 for anyone other than OML unless you have 8 covers (10 for SS or probably Spidey).

If you have a single or multiple non-top tier 4*s only:

Why would you have done that?! Submit a ticket and beg to get your precious ISO back.

FYI: I didn't level my OML until I had 6 covers (3/1/1) and I don't regret leveling him at that point. I had HB, XFDP, Thing, 4cyc, JG, and Carnage champed. I currently have OML at 375 (5/2/1), same champed 4*s and I haven't leveled my SS (2/3/3/), Phoenix (2/0/3), Spidey (1/0/1) or GG (0/0/1). And looking back, I have no remorse in waiting that long to level up OML. Honestly, I didn't find him more powerful than my 4*s until he got to 360 (I think about equal at 345).

Not super helpful to the discussion, but I've been wondering the same thing, and asking alliance-mates and BC-mates every time I pull a new cover. Recently got phoenix and SS covers to get both of them to 9 covers so was wondering if they were worth investing in. I think the consensus at that point was yes. (For reference PHX is 3/1/5 and SS is 1/3/5)

Also, talking to other players about it, it seems 360 is kind of the point you want to cap your 5* without messing up your MMR into being "5* player" and getting into q-hell scenarios. This level might also depend on your 4* and what they are capped at/get boosted to. If you have 13 covers and can max them, then you probably don't really need to worry, but maybe at that 9-11 cover range you want to stay at lower levels? I obviously have no experience with it, just passing on what i've heard.

I agree with Tarheel. I've talked to a number of people about this and two 5*s at 360 (or one at 390) seems to be the tipping point. I've been keeping both my OML and JG at 345 and haven't noticed any changes to MMR yet.

Having OML/JG at 345 has been helpful, but not exactly easy street - I still can't quit float over 800 with them. These past couple events are tough to measure by too though with IMHB and JG being boosted, I'll experiment more here in the last few events of the season with some different boosted 4* characters and let you know.

I think to have 5*s that really have a noticeable impact you have to get them up over the boosted 4*s which throws you into 5* MMR (which makes sense now that I think about it - once your roster is beyond that of a boosted or max champed 4* time it probably should have higher MMR).