When Strix goes into stealth, he's fairly loud, allowing you to be able to more accurately predict where they will be. Strix usually hides and peeks to shoot, but shoot once, teleport mid-long range, and he's toast after the second shot.
To counter Viktors ult. If he ults to you,press reversal and press S on your keyboard or your backwards button while on reversal and aiming on viktor,or once your reversals almost down you can switch your aim to other champs if youd like to
When playing against a strix as sha lijn strix will be a better long range duelant. Try to hide behind rocks a peak out on different spots For Some free damage.
Nullify makes BK completely useless. For talents if you know the how good the enemy BK is (from previous matches), BK is the only dmg or your other talents would be useless in the match pick the Direct Current talent to make it harder for BK.