If the enemy Ash doesn't pick up Resilience or the "Battering Ram" Legendary, then you can punish her for it by saving your hyper beam to knock as out of her ult's safety circle. This will often waste her ult or her movement ability.
You are not CC Immune when you ult. A smart Torvald can use his Hyper Beam to waste your ult. To counter this, consider Picking up Resilience if you can trust your team to help you deal with Torvald and his team.
You can encourage him have to get close enough to shoot by using the shield Legendary to block shots and give him room to advance. If he tries to contest you on point then you can use Kinetic Blast to knock him off and use your shield to stay safe.
Most of your abilities (including your ultimate) have long and noticeable startup times. Torvald's Nullify will interrupt those, so wait until he uses it or buy Resilience to reduce the downtime he can cause.