This match up depends on your timing and his aim. If you get lucky and time his shot with you obliterate his follow up shot won’t be enough to win the fight.
Viktor's ultimate is reliant on him having direct vision of you so moving out of sight behind a corner or using opaque deployables(such as Inara's wall) will prevent him from selecting your location.
The easiest way to play bk is to sit in the back-line and throw bombs. If you want a challenge try using the poppy bomb to launch you across to the other side of the enemy and wreck! Don't stand in one spot always be moving!
If you happen to see a makoa and don't have any teammates on you, just back off and poke him if possible. It won't be long till one of your teammates
Joins in. If so. Take him out toghether and try your best not to be in his hook range.
Unlike most front liners and supports grover has very good long range pressure. He can use his bonus damage scaling legendary to harass enemy front liners from long range or long range enemies from the objective easily.