Very simple build idea here; we're taking Jub's fantastic "20/20 Vision" setup and tweaking just a couple of artifact choices and our teamup to turn Vision into the first choice, most valuable overall team slot atop the entire hero roster (in my opinion of course). This quick writeup doesn't go into the mechanical details of the skill rotation, how to double beam weave with Vision, etc; go check out that aformentioned guide from Jub if you want to learn how to play the character at a high level. 

Long story short: get to 50% cost reduction (this is a hard cap; you don't get any further benefit past this!) and Vision's signature  will be reduced to a paltry 17 seconds with a cosmic sig CD affix. This enables high uptime of the on-signature proc of  (make sure you get a good roll of power duration on ) and near full uptime on the ground based portal of , which will both apply to nearby allies, not just Vision himself. These are not quite BiS artifacts in pure "TTK" terms... but with Vision's particular damage profile they are close, highly competitve choices on a hero that's already knocking on the door of top 5 overall DPS among a roster of 63 characters total. We will gladly take the slight hit to the tip top end of our damage in exchange for an appreciable amount of group utility that's quite frankly unfair on such an already strong hero individually: +2 to all stats and 9.5% attack speed for everyone at (almost) all times! A juicy 1300 crit damage on top of that for anyone who remembers to stay on top of the power portal. Don't forget Vision is also providing permanent weaken (and Power Doop) uptime courtesy of ! And it doesn't stop there; we're utilizing every available itemization slot and teaming up with either of the Sorcerers Supreme   or   to add Toughness, Power, and Constitution auras into the mix as well. These buffs from our teamup are admittedly low duration/uptime... but as you'll see below this is sadly still more than the heroes themselves can provide in some cases. The increase in "damage"  provides over other active teamups is less than negligible and not at all worth it for anything other than TTK chasing on the training room dummy; Strange and Clea's buffs and grouping are much more worthwhile in comparison IMO. 

Marvel Heroes isn't a class based MMO; there are no dedicated support, tank, or healer heroes or anything remotely comparable to them. The best "support" a hero can offer to the rest of the party first and foremost is dealing the most amount of damage. Any groupwide effects that are available to make use of are usually negligible in potency, uptime, etc. You may have seen some Invisible Woman "support builds" that utilize the  with full uptime on the portal due to her multiple, low cooldown signature charges... but IW is sadly fighting among the BOTTOM 5 of the roster in terms of damage. Doctor Strange is a strong, competitive hero with party-wide offensive and defensive buffs... but unfortunately one or both of these powers are bugged and don't actually apply to allies (Yes, teamup Doctor Strange is currently a better team buffer than the playable character...)! Vision when piloted properly, snapshotting his dots and weaving his channeled abilities correctly, is a comfortably top 10, borderline top 5 hero in terms of DPS. And is able to reach this output with plenty of allowance for the few artifact choices that do provide a tangible, functional/not-bugged (to my knowledge at least) benefit to other players. His damage output is also by far the most consistent of the "top tier" heroes: he is not at all reliant on brutal strike slot machine RNG like Juggernaut. He's not a "bursty" damage dealer with major swings and requisite downtime like Blade or Mr. Fantastic. And his damage layers aren't summons whose health and targeting needs to be managed like Rogue. The sole "summon" he DOES use via  is a funtionally unkillable meatshield that can shrug off cosmic difficulty boss telegraphs and draw enemy aggro/damage away from him and his teammates. Call it clickbait if you want, but all of this considered is why I am comfortable calling Vision with this setup the MVP, the "first pick off the board in the 63 hero draft" so to speak, when it comes to group play in Marvel Heroes Omega. Maybe a perfectly played Pulsar Nova can argue to the contrary... if the carpal tunnel and hand cramps don't get in the way ;)