I finally 100% explored Back Issues #4 today and wow the rewards were everything I dreamed of. 😛 Thirty units richer and my 5 star Wiccan (who I pulled from the 5* crystal) now sits proudly at Sig 100. Incredible return on time invested. 🤣 But yeah I’m really just doing these to finally finish the content I ignored for years. Two more Back Issues to explore and the set is complete.
You might as well grind the arenas
That wouldn't give me the same satisfaction as knowing I've 100% explored all the Variants.
It’s going to depend on your roster - IMO if you’re a lategame player the Moon Knight variant is the most annoying because you can’t just plow through with a bunch of 7*s. Ant-Man is fun, buffs XL champs in general and each quest is tailored to a few specific options. Magneto is also pretty easy if you have Sentinel since he gets extra bonuses, but it also works with tech champs generally.
The Ultron one is not super hard but it’s really long so it ends up being a bit of a slog.