I was talking to my alliance mate and I realised that each of us have our own individual “unicorn”.
For me it is Iceman. After 2 seasons worth of LT, I have only gotten one green cover for him. Coupled with the progression reward I got a blue cover.
So I am still missing an ice man purple. I have given up on maxing him for the next few seasons.
What is your personal unicorn?
HB red. I had a 2/4/4 as his double release ended. I gained 1 black cover since. Finally whaled him with the sale.
My new unicorn would be Red Hulk. My NoN vault is littered with 4 covers of him. Naturally I only pull ISO in the form of 2/3 stars and 10CP that give me an LT with a JG I already have maxed.
#firstworldproblems
Carnage 
is my Unicorn. I have him at 5 covers in 
and 
but for some reason I cannot get that black cover.
probably x23 green. That’s the only non 
cover I’m missing. 
Iceman in general
and…
Black Panther
…DDQ the other day was only the second black I got for him…where arrrrreeeee you!!!
Look on the bright side: 505 carnage is VERY usable. 
Same as above. For some reason, I haven’t managed to get any Iceman covers except for earned placement and progression reward, and one I earned when I got him from his PvP event vault.
I have had a few 3*s that got to 5/5/0 or similar in the past, but the most annoying ones for me right now are PX blue and JG purple.
3 star Steve rogers yellow, the one dpd I missed was his yellow! Stuck on 024. All my other 3 stars are pretty much fully covered..
3* transitioner here. IF is the only 3* I haven’t ever pulled from a token. I got a cover from placement in pvp and 1 from DDQ. That’s all.
Oddly enough, SL yellow… he has been 5/0/5 forever.. his most useful cover…
Every 5*. No problem getting MrF and Falcrap from Legendaries though.
JG blue (current 1/0/5) and actually XFW. Only ever pulled 1 yellow for him, the other covers from daily resupply. Sounds like everyone else pulls his covers like crazy
Rulk purple. Since his release, I’ve managed to get 4 green from random pulls, but 0 purple. And 3/5/1 Rulk is way too slow to be useful Rulk.
Hulkbuster
Mine is 0/5/4 so still no chance in the 4* DDQ.
I’m looking at my Falcap… 5 yellow and 5 blue but no red. It’s got to be that one 
Used to be
for Black Panther, had that at 4 covers forever. Now it’s Iceman. No luck pulling any of his cards yet. On the other hand it seems like every other token I open is a Rulk. So no complaining here, but the search for the elusive Bobby Drake continues…
Carnage - I am on day 790 and he has yet to grace my roster with a single cover.
Iceman blue. A legendary teased me earlier today with his green.
X-Force 
Those 3 are my unicorns