Buck is a mid/good option for dealing with strix, Get illuminate and start searching for him, he can take you out in 3 shots if he can hit you while jumping, be as mobile as you can and use your net to capture him and kill him quickly
If you're playing against a Strix, your best option is hit 1 fully charged shot before he goes invisible, then remember, Strix is a peeker, he will peek to get his shots while invisible, try to predict when he might peek or where he might be and won
Your ultimate goes through his shield. If he survives it, no problem! Spite still cancels his shield! Use it when he hides behind his shield with low hp, especially when he uses Last Stand card!