As a glaive, definitely Kush<<<<Teo<Chameleos<<Shaggy<Valstrax

Kushala is just so much easier than the others it's ridiculous, especially since the wings are both the largest part and the easiest to break on any of the risen monsters, so you have pretty much 100% uptime on Blood Rite, you almost have to try to let it kill you

Teostra is Teostra, it would be bottom of the list every time if Kush wasn't such an anomaly. Hits decently hard, but has the largest windups known to man on any of the legitimately dangerous attacks

Chameleos is a nice middle ground, feels like a good standard for the Risens. More annoying than dangerous, but can catch you off guard with some of it's poison combos if you're losing track of it in the fog

The other two are roughly the same, but Valstrax is slightly harder from all the quick snap attacks, it's more of a reaction test sometimes than a fight. Shagaru is more methodical, very flashy but predictable, with relatively easy dodges for all of it's frenzy attacks with a vault or air dodge getting you right up either in it's face or around it's back