Warframe

Revenant is the king of not dying, and while that's not all that much it is all you need to succeed in endurance if you can mod weapons well. He is the most relaxing and least-demanding option. His 1 and 3 combo to deal percentage damage to enemies, so they scale infinitely. There's no better frame for endurance, though he's not that great of a pick outside it.

Alternatives include any frame with invisibility.
Loki gets both invisibility and invincibility courtesy of Safeguard Switch, so he's one of the safest frames to play provided you have your timing down well (or just spam your switches).
Ivara has to handle prowl's limitations, but if you're able to (You can use power strength to boost her base movement speed with her augment, and archon shards to increase the speed of her roll with the parkour velocity stat) she can be a devastating killer.
Ash is a complex mess. He is both simultaneously great and terrible, mostly because he has an overwhelming need for augments to patch up his poor base kit. Note that Bladestorm carries Ash hard, and is an ability that has (some) damage that scales off your melee in a very strange way. AznvasionsPlays made a video on it here and the ability will still handle endurance without the bane nonsense.
Voruna isn't a terrible choice, provided you can handle either recasting her 1 after every single heavy melee attack for a surprise melee build or manage a pounce build using her 2 and 4. The former requires you have a very good weapon for heavy melees that can wipe groups in single swings, which isn't too hard to acquire but does mean you need to know especially what you're doing. The latter is easier but does require quite a bit of setup and can be especially slow at times due to the RNG of her 2. Basically, you use her 2 as a primer and her 4 to knock things down. The latter build is expensive, though, as you'll need very good energy economy either from yellow archon shards or arcane energize (as her 3 is completely useless in this build, subsume over it with Roar, you'll need the double-dipping damage boost).
Octavia is known as the queen of... well, everything. Provided you can handle spamming your crouch a bunch, setting her music to hit every beat means you will (almost) always have the buffs racking up on accident, and thus will always be invisible. Combine that with her mallet that scales off enemy damage when they target the thing and she can easily clear just about any threat as long as it touches the mallet and not her.

As for good shield-gaters, there are quite a few.
Harrow is an obvious option, but he can be quite difficult to play at high levels.
Hildryn is another option, but she can have issues between balancing ability strength to full-strip with pillage and managing her shield to not die (especially against infested). Not a terrible option by any means, but you will have to decide between full-stripping and having issues running Hildryn with too many allies (as they will steal all your shields via Haven) or doubling the pillage casts needed each mission. Wisp is a decent option. She's technically an invisible frame, she's invisible as long as she doesn't attack and doesn't touch the ground (or as long as her 2 is active) but she's effectively a shield-gater since you will need to attack at some point and her 2's normal use in endurance is to grant you invincibility at the end of it, not the invisibility during it. For obvious reasons, her health motes are largely useless at such a stage in the game.
Protea is an alright option. Personally, her 1's shield refresh is a bit slow to cast and she doesn't do amazing damage with blaze artillery (but they are heat so they'll function effectively and kill things quick enough) but she can do endurance better than a lot of frames.
Volt is a good option. Capacitance allows him to charge his shields effectively all the time, so he's actually one of the better shield-gaters provided he's well built.
Garuda is also an option. Combining her 4 (which grants invincibility during casting) with Wisp's 3 as a subsume allows them to chain off each other, creating a slow run-away reaction that can kill everything and everyone in the vicinity. Using her 4, in-built 3, and Molt Reconstruct means she essentially has all the energy needed and all the health to supply that energy, and her 4's invincibility period combined with augur mods will let her shield-gate effectively.

As for the special snowflakes (other than Revenant), there's Zephyr and Valkyr.
Zephyr is invincible provided three things: You build range, always keep Turbulence up, and never let anyone melee you. Building range on Zephyr is the easiest thing to do, every ability of hers wants it and she can easily drop strength. Keeping Turbulence up is as easy as Natural Talent (if you even need that) and not forgetting the timer. Never letting anyone melee you is as easy as holding her 1, which will let you float in the air as long as you have energy. Now, unfortunately there are a few things that do get past Turbulence these days (cough Thrax magnetic beams cough) but you should be able to easily survive even against those kinds of things if you keep your wits about you (and have Rolling Guard).
As for Valkyr, she's the immortal kitty who cannot die so long as she has energy. That's pretty easy to accomplish, but the real issue is now you have to use her meh exalted weapon instead of the numerous better things you could be using. She's not my first pick for anything, but she works.