When playing Vivian note that you can cancel your shield, I see lower level players keep it up when they aren't using it which means they have to wait longer to be able to use it again.
Skye is a big counter so hear are some 3 tips to counter her 1: try to stay close to your team and try to flare your back 2 : headshot her and pistol her down but is hard 3: make a deck with ROOST on lv 5 so is hard to kill you when you are scoping
When terminus uses his ult to get back alive, use reversal. If you time this ability right, you can fire over 3000 damage towards terminus and let your teammates or yourself finish him off.
This applies when you are fighting ANY champion, use Khan's ability where he can pick up enemies to throw them off the map, this is very useful if the map has many ledges you can chuck enemies off.
Vivian's shield only protects in front of her, use a flank champion such as Skye to attack her from behind. With any champion you should still try to attack her if doesn't notice you.