Variant 4 100% might be worth it if you have a 1* hulk and a good roster with lower stars. You should be able to beat that electro with quake and skill. It’s definitely one of the better variants in terms of rewards vs difficulty. Variant 3 is also pretty good. You have a ghost and warlock which are 2 of the best options. If you had a sentinel, it would be even easier but you don’t really need him for completion. Variant 1 and 2 are both long and much more challenging. Honestly, the rewards aren’t worth the struggle unless you’re ready. V2 is easier than v1 but definitely not better than the newer ones. Variant 5 is going to limit you a lot. Long shot, Morningstar, clairvoyant, symbiote supreme are great mystics and will help you. Stealth spidey is great too. I don’t think you’re ready for V5 tho, because you really need more options. Stark spider, venom, venom the duck, doom, carnage, Mephisto and voodoo are all really useful and will come in handy. For example, there is an iceman and Mephisto is one of the few counters. TLDR; V4 100% or V3 completion. Good luck