@lordalmighty1 You must not have played revenant or looked to carefully in the patch notes. You can still take 100 damage, but you'll respawn with 50 health, and all your shields. (Or, whatever health you had when you entered the totem.) This was a straight up buff.
You can still do a lot with Revenant totem, especially if you surprise someone. If you laser them out of nowhere, they'll drop or at least have much less health and be a lot more vulnerable. Plus, just today, I got into a match in KC. Final 3, the other squads had downed one of my teammates. I used the totem and then went and got my teammate with very little risk to me. The totem is really useful. A lot of your point was kind of lost because it actually doesn't reduce your health in shadow form, just when you die in shadow form you are respawned with 50 health.
Well yeah, if you use the Pylon out in the open it can be shot. It doesn't provide immunity to bullets to your teammates either. Even if they shoot it as well, if you have an accelerant Wattson can basically instantly put up another Pylon. (I also think her ult charges even with a Pylon out, so you don't even need an accelerant.)
The Pylon also basically lasts forever, whereas Gibby shield lasts for like 10 seconds and has 30 second cooldown. Well, yeah, Gibby has a unique ability that can do certain things well. There just aren't enough legends to have many overlapping abilities, so yeah his dome will be unique.
A whole squad affecting, multifunctional ability. How about Wraith's portal? It can be used for many situations, like retreating, or teleporting a knocked teammate to safety, or rushing, or tricking the enemy team.
Or, again, Revenant ult, which can be used for a lot of things too.
There's also Bloodhound's scan, which is really good. Not really multifunctional, but it's a really good ability, especially with the distance buff.
His bombs aren't necessarily better than Bangalore. Both of those are more situational based, each with slightly different situations. His dome shield isn't necessarily better than Wattson's Pylon. The dome shield also blocks your bullets too. His dome isn't always better than Lifeline either. Lifeline is always available to help teammates, whereas Gibraltar has to wait like 30 seconds between dome shield, and his dome shield is very visible, practically a flare for enemies to come and third party you.
Also, with what heme725 was saying, Gibraltar wasn't op before his more recent buffs. He always had had these abilities, but was just a throw character.
I'm not saying he isn't strong, but that doesn't mean he is op.