can you feel my heart?
Well, hopefully you can get those EVs to us ASAP because we can't do too much without them. ;o;
Heatran needs needs needs Flash Fire. It loves the ability to absorb Fire-type moves - that's what makes it so good! I also like running it with Air Balloon so you literally only have one weakness until that Balloon is popped. It also lets you have a makeshift Excadrill and Landorus check if you need it. It also wants Fire Blast > Magma Storm (accuracyyyy ;o;) and HP Ice > Explosion. Explosion got nerfed this gen and it's just really not too good because it doesn't do nearly as much damage as it used to. Therefore, I'd pop Explosion off of Magnezone too if you can, and run HP Fire in its place so you can smash Forretress and Scizor when you trap them.
Also, CB Scizor wants Bullet Punch > Bug Bite. U-turn is the only Bug-type move it needs, tbh - and the access to such strong priority is definitely one of the best reasons to use Scizor.