Slayer could use some raw damage reduction and/or some health regen (not temp), plus a bit more maximum health. Temporary health on hitting targets with Leap, or a small lifesteal passive would/could help too. The reason I say this is that Slayer needs a little more raw room on the leash to make mistakes as I’ve seen more than plenty of people go down a lot faster and/or more frequently with Slayer than any other career, and they’ve said that the extra bit of speed with killing isn’t worth it.
Leap should also should force enemies away from him as to prevent being crowdsurfed (unless that’s been fixed, I don’t really play Slayer), and it doesn’t like to go all the way to the center of where you aimed, (ie it drops a little short). Trophy hunter could probably use an extra second or two of duration, and Dawri Drop should get a (very) brief period (half second or so?) in which it allows for the extra damage to be used in case of nearly getting that strike rather than being only while midar.
Yes, Grimnir’s Focus allows for a 40% damage reduction for short period upon a successful heavy attack, but doing such tends to mean you’re not likely to be using the dual weapons the slayer is good with ,unless you hit with a charged attack via Leap. 2H hammer/2H axe what you’d be using with GF,
Oblivious To Pain is a guaranteed 50% damage reduction against elites and monsters. This results in OTP being better overall for plenty of people on most (if not all) difficulties and using a variety weapon types, but isn’t really great in general when the vast majority of the time you’re going to be hit by anything except elites and monsters/bosses.
Comparing the two, I think duration GF’s duration should be increased by a few seconds (8-10) to make it last a bit longer, and that OTP should get a small 15% damage reduction vs anything other than elites/monsters.