This is just a compilation of combos for infinite combat steps. All of them require a few more cards than are listed, but they give the basic idea.
Aurelia
You also need some creature to cipher Stolen Identity onto that will be able to keep getting hits in until everyone dies. The way it works is that you attack with that creature and Aurelia and then copy Aurelia with Stolen Identity, sac'ing the old one to SBA. The new one hasn't attacked yet that turn, so on the extra combat step of the first one, you'll be able to get the trigger again, ad infinitum.
Waves of Aggression
Now, this one is really crappy and stupid, but you can do it, so I decided to go for it. Basically, you need some way of drawing at least one land each combat and some way of getting enough mana each combat step. For the first one, you need to either draw a lot of cards each combat, or stack your library with lands, which would be easier with Green. But, we aren't using green here, so I just listed a lot of things that will draw you cards each turn. For the mana part, any old infinite mana combo would work, but since we're doing Jeskai and it involves infinite combat, Sword of Feast and famine would be an easy way to pull it off. Paradox Engine works too, either using [Narset, Enlightened Master], or just by getting enough mana off rocks and casting some of the crapload of cards you drew.
Combat Celebrant
This is another fun one to me. The easiest way is to use Combat Celebrant with Kiki Jiki or Splinter Twin to untap the original and create a new copy every combat, which won't have been exerted yet that turn. Another potential way to pull this off is with Stolen Identity and Fervor or some other mass/free haste granter, which would have roughly the same effect.
Aggravated Hellkite
This one is fairly straightforward. have Hellkite Charger/Aggravated Assault in play, have some way of making enough mana each combat, and keep swinging. Again, we're in Jeskai here, so SoFoF is a good option, as is Narset with paradox engine. However, if you're willing to branch into green, [Savage Ventmaw] with either a copy or something like [Training Grounds] would do it to.
Breath of Fury
This one doesn't use many different cards, but requires a fairly precise use of the stack. In this one, you have to use Kiki Jiki, Splinter Twin, Hanweir Garrison, etc to keep producing a new token every combat that you can bounce Breath of Fury onto. Using Stolen Identity or Hanweir Garrison requires some form of haste granter, however.
Lightning Runner
Possibly the most niche one of these, this requires you to create eight energy every combat to pay for Lightning Runner. Thankfully, it produces two energy every time it attacks, so you could just make 4 of them using any copying method, including ones mentioned in here or others, such as [Rite of Replication]. There are also other creature that make energy whenever they attack or deal combat damage, so those would fill the role as well, but why bother when we already are making so many goddamn copies. Another option is to use something like Aetherstorm Roc with something like Hanweir Garrison that can make a bunch of tokens every combat and give you energy.
