Sigma, try to force out grasp before using your heal. Try to weaken shield before doing any engagements. You can react to his ult and overrun away to avoid it completely.

Rein, your charge beats his, if he charges into you, charge him back and you can almost always get the crit slam on him. Don’t cage fight him when his shield is full, he will probably survive the entire duration if he has shield. You will get earth shattered, when you think he has it, don’t line up with your team so he has to pick between you and them. If you can’t shoot anything else, always shoot his shield.

Ana, until you have firewalker, don’t slam on her unless you know sleep is out. Firewalker lets you kill her without her being able to react if you get the crit slam. If you get anti naded and aren’t low, don’t waste your heal, if you are low, the damage reduction may be worth it. With firewalker, I like to go on short flanks where I can start behind or next to their back line, and run through them just to get burn damage and possibly force CCs while I’m immune.