This match up is extremely interesting and I shall break is down into two sections
Valk form
In human form valk has great pokes and generally excels in the neutral game over you. He has more range and gets a good knock down on any of his pokes, you need to find the sweet spot and start baiting and punishing his pokes. His most used pokes are 5b or 5c get use to there ranges. Your 5b is faster than both of these so remember that and use it when needed 6c is also a good poke as it pushes you forward, just remember to cancel it with an asteroid vision if blocked. Valk doesn't have the best air to air game so that is the best place to confront him. Makotos jc can lead to some simple combos and as always go for the j.b counter hit fishing. Valk still has some strong mobility tools using his wolf form to launch him, be careful for the j.c rc j.c its a nasty double over head. Jumping in on valk is a bad idea 2c will trade (will trade with tail of destiny )with just about all your air moves in his favor and you'll get corner carried. 6a also has a guard point and can be a decent defensive tool but its a big risk for valk.
When you are in the corner 6c is valks best pressure tool as it breaks a primer and leaves him +2 so keep a close eye on his pressure. 6c is relatively slow so if you can keep an eye out for you can parry on reaction or DP. He can pressure you from a pretty safe distance you just have to keep an eye out for his lows, they lead to smaller damage than his overheads but there range i still excellent. Valk is looking for knock down so he can apply wolf pressure or corner push. His normals are decently safe. 2a will make you eat quite a few things so don't mash out and just focus on IBing and looking for that escape.
When you get in on Valk it turns into a really bad situation for him. His defensive options terrible with no reversal other than a wake up sturm wolf which nets him 2.5k but he loses the meter. So feel free to pressure him and just go all in against him. You can back off a bit when he has 50 meter but overall its not that scary. When he gets 100 meter he can rapid a sturm wolf to make it safe or rapid it for 5k damge His back dash is decent invul and becomes his best meterless defensive options. 5c has a ton of active frames and will catch his back dash a lot so feel free to call him out this tool. Or you can just use dash a2 5b and force him into a block string.
Wolf form
As we know Valk loses his defensive options in wolf form so Orb becomes a pretty decent tool in limiting his options. using it just to cover some space can limit the amazing mobility he gets in wolf form and can make his advances put him in an unfavorable situation, use sparingly as you can be punished. But its a decent option to start learning how it works and what you can do with it. Using a charged orb to call out a wolf dash can net you some great damage with a dash 2d. Don't jump in on valk in wolf form as he will 5b and you eat a good combo. Valk in wolf form puts you on the defensive so you are trying to keep him out for the most part. Once he gets in his high low mix up becomes insane and very difficult to deal with. Stay calm and remember he can only do it for so long before he has to recharge. When he gets a knock down he can easily bait your dp with a back dash in wolf form and then make you eat another combo.
Air to ground
Wolf cannon(as a I call it) can be beat with 6a, i have yet to figure out the timing on this. 6a is still a risk he can space it so he lands in front of you and he will recover before you do for an easy punish.
air to air
Not much to say but this j.b is a good option as it covers the most space but wolf cannon can still beat it if your movements get predictable.
Overall - This is a strong momentum match up. Keep him cornered and limiting his wolf form movements are key to success in this match up. Most valks with be switching between wolf form and valk form constantly so you need to switching game plans as it goes and remembering your options and what you can do. He is extremely scary and great at busting primers with his 6c pressure in the corner, keep an eye out for those. Once you start your pressure just go in and keep him on his toes.
Gotta give props where props are due. Willy owns jury duty for free. Real talk.