Keep the outline/cel shading, it makes it look more "stylized" and fun! Amazing work and it reminds me somewhat of DOTA2's or LoL's art direction. CHEERS! :D
Awesome work man! I say keep the outline.. I love those concepts and like that you're keeping it more stylized. That's some good sculpting too! The only crit I would give is that the skeleton looks a little light... as in weight... I think you could try to push that a bit, try to make his pose look like he's hanging a bit…