Zealot does not gain extra toughness from Vicious Offering when killing an enemy with the first heavy attack of the Crusher, but does gain extra toughness with the second heavy attack.
The video showcases the light attack kill, then heavy 1 kill and finally heavy 2 kill.
Worse yet is that for some reason I had an instance where killing with the first heavy attack restored less toughness than killing with a light attack.
console-2023-11-22-19.35.33-86c2d81a-8382-4691-b240-ee7e69da6c8d.log (1.9 MB)