Some people will not like my comparison but in all honesty, Joshua Leivo reminds me most of David Backes. He's got size, he's physical, he's got speed (not blazing fast but fast enough), he can fight, he's got soft hands, he can play excellent defense (I believe he was voted #1 and #3 top defensive players for the last 2 seasons in the OHL?), and he's noted quite highly for his character and leadership in juniors.
Carlyle went with the Kulemin - Kadri - Lupul line towards the end of the regular season because Kadri gets 2 physical wingers who can both dig pucks out from the boards. Unfortunately, Kule's offense dried up these past 2 seasons but Leivo in the not too distant future looks like the perfect fit for that line.