Theorycraft: Most Game Breaking R.A.W Legal Combos

I'm curious what the most game-breaking combos that are RAW legal for players, and don't require homebrew, specific magic items, or rolled stats. This is pure theory-crafting, anything that fits rules as written, regardless of if it would be allowed by any DMs.

Please share your best combos, and whether they're using 5e, 5.5 or both.

The One-Man-Army: (using 5e)

The build requirements:  L17 Order of Scribes Wizard, Witherbloom Student Background, the Cartomancer feat, and knowing the "Wish" and "Teleport" spells.  

Tactics:

Your first line of defense is endless Familiars (falcons, owls, ferrets, cats, etc. created by your Simulacra) circling you at a roughly 1-mile radius, to check every nook and cranny for any potential threat, be it monsters, people, glyphs, traps, etc.  You have some Homunculi mixed in, so when Familiars which are out of range for their telepathy spot something, they can go to the nearest Homunculus and bring it to see, which informs the Simulacrum that created the homunculus through the shared connection.  

The second line of defense are groups of reconnaissance teams (of Simulacra) about a half-mile back from the circling familiars.  They're the ones who created the homunculi out with the familiars.  If anything gets past the familiars, they're here to intercept it.  If they're engaged, or are notified of a substantial threat spotted by the familiars, one of them uses Mold Earth to fill a bag with material, and used a banked Wish with Hidden Ace to replicate Teleport to take himself and the bag to the staging area.  The reconnaissance teams are accompanied by the homunculi from other simulacra at the designated staging area in a secure location.

Another half-mile behind the reconnaissance line is the original caster, who's accompanied by a handful of Simulacra body-guards, with some homunculi created by simulacra stationed at the staging area overhead. Underground are many Earth Elementals, summoned and planar bound via the Hidden Ace Wishes of the Simulacra.  Any tunneling monster or embedded trap will be confronted by a multitude of Earth elementals.

At the Staging Area, there's a number of Simulacra stationed, along with the rest of the homunculi not with one of the aforementioned groups.  Any time the Simulacra here are notified by their homunculi with the reconnaissance teams or the original caster, they assess what level of response is necessary and notify the appropriate number of teams of Simulacra elsewhere in the world, through their homunuli stationed at the staging area for this purpose.  The bag of material collected by the reconnaissance team is spread out to be easily accessible by the teams teleporting in to the staging area.  Then teams of Simulacra teleport to the Staging Area (one member using Hidden Ace's banked Wish to cast Teleport to bring them here), then a second member of the team picks up a bit of material from the reconnaissance team, using it as an "associated object" for the destination location so there's no chance of the spell going wrong, and uses his own Hidden Ace Wish to teleport to the combat, as the rest of each team have their actions readied to use their Wishes to replicate an appropriate spell for the given threat (L9 Fireball, Disintegrate, etc).

So every combat should be completely resolved within seconds of starting, long before getting anywhere near range for the original caster.

Mechanics of how to pull this off:

Day 1, use Hidden Ace to bank Wish, and then use that Wish to replicate casting the spell, "Simulacrum" to create a simulacrum of yourself.  Then take a Long Rest, so you and your Simulacrum both refresh your Hidden Ace feature (which isn't a spell slot).  You instruct your Simulacrum to use the Hidden Ace banked Wish to replicate Simulacrum to create its own Simulacrum of the original caster, order it to obey your orders as if you were the original caster, and instruct it to give its Simulacrum all of the instructions you gave it.  Then every six seconds, there's another duplicate of you, with half your hit points, but all of your spell slots, only having used their Hidden Ace feature, which does come back on a Long Rest.

They'll all always bank a Wish spell with their Hidden Ace features, which they use to create their own Familiars and Homunculi, as well as summoning elementals and planar binding them to guard the original caster and any other locations important to him.  You then stage the lines of defense around you, with the excess Simulacra in teams of 8, the maximum that can be transported by the Teleport spell.  You can send teams of Simulacra to libraries, universities, distant kingdoms, anywhere you want that they can collect information to pass on to you, so you gain the benefit knowing all of the information they've collected, and while they can't learn, the future Simulacra created of you will know the additional information.

When you have more simulacra than you could possibly need, even to stop Tiamat, the Tarasque, or Vecna, you can have the excess establish their own cities.

5.5e Suggestion + Planar Binding + Magic Aura

Suggestion is pretty easy to get access to as it is only a 2nd level spell so you can have your whole party spam that to get through an enemy's legendary resistances, then Suggest they stand still and choose to fail the save against Planar Binding, enabling you to cast Magic Aura to make then the correct creature type then be enslaved by Planar Binding.