Kal's Plate should protect him from most attacks. If not, he can just heal using Stormlight anyway, and then would only need to touch Guts once to Lash him into space to die. Been a while since I read Berserk, but I don't remember Guts having any counter to that kind of hax
Maybe Guts can take 2nd Ideal Kal since he hadn't fully mastered Lashing yet, but anything above that I doubt. .