Iori: Staying in is going to be important. Most of Iori's reversal options are good up close or point blank. Make use of your farther reaching normals to confirm into max mode if they whiff a lot of st.Ds.
You can make st.D whiff if you do strings like d.B, d.A, d.B, st.B. Any subsequent normal will make them whiff. You can stagger the d.B into d.B, st.B, but you're still in range. Be sure to step back a little.
Try to incorporate frame traps into your gameplan too. This is universal, but King, Iori, and Kyo all don't have grabs so any reversal in between a frame trap has to be beat by normals or reversals. Stuff like d.B, st.C or staggering your normals will let you open up people.
Kyo: Use your longer normals to poke and pressure (St.B, far C, far D). If he starts using rekka to out poke you, throw out some d.Bs to check him.
Be very strong with anti-airs and don't let them get solid hits. df+C is your friend as well as far D. If they get the hard knockdown, try to mix between backdashing to bait out meaties or checking them with a d.A. Kyo players like to get in close to go for meaty pressure or bait reversals. Backdash on wake up stops that, but don't do it too much.
King: Pretty much the same thing as mentioned by WildWolf. Also remember that crapshot, her flip kick, is lower body invulnerable and has a wide hitbox. Don't give her any room. Everything she does is unsafe close up.
Use frame traps and hop pressure to keep her pinned down. If you get about 2-3 character lengths away, they'll stop throwing fireballs. If they don't, hop over them on reaction and punish. If they do, they are going to retreat or attack to keep you from being in their face.
Some people like tornado kick, but that's not safe. Some will slide. Test them to see what they do or if they switch up. If they like to slide, hop up with j.D and land on them or backdash to make them whiff. Once you're in their face, stay in their face.
EDIT: You can ALSO full jump early j.CD. Terry's J.CD has a really big downward hitbox and forward hitbox. If you read when someone is gonna tornado kick at you, you can just early j.CD and hit them clean/trade. You'll do more on the trade though.