I'm going with Gvozdyk, who fights Stevenson next. Gvozdyk is tall, technical, and powerful. In his prime now at age 31, he should de-throne the older Stevenson.
I rate him very highly, he has amazing footwork and positioning which makes it very hard to hit him clean and he has a great jab, punching power in either hand and determination to the sport. I don't see anyone who is better in the Light Heavyweight division right now.