I know cydstepp has been changed a few times. I wasn't around for this.
Essentially before the CYDSTEPP change, everyone could use it repeatedly like the Warlord can. They ran through a couple iterations before settling on what we have now.
1)For the next attack, your resists are set to 75% and ignore your cursed status.
This would prevent it from being used as a prebuff ahead of time, and would likely render it completely useless for many classes.
2)Must have over 50% hp to cast. Warlords are not exempt, but get some other bonus(cheaper mana, can cast if above 25%hp, something else?)
The problem with 50% health is that this makes it better for rogues than anyone else, which is exactly the opposite of what you want. This is because rogues still heal at the same rate as everyone else, but their max HP is much lower. On the other hand, people with very high HP basically couldn't use this glyph.
I believe the *right* way to do this would be to have a minimum HP amount to activate CYDSTEPP; 5 per level would be about right. This would mean rogues would need full (or near full) HP, while everyone else could activate it around half-health. I do think Warlords should be exempt from any such limitations, though. Death protection chaining is what they do and it's fun; if the class is too strong I'd prefer to see it balanced in other ways.
It just seems cheap to chain Cydstep a dozen times.
I remember back when Dracul had a +2 mana boon, and had a repeatable "blood tithe" effect that traded off 10 max HP for 20 piety. Enter the Rogue, who traded all his HP away for max mana and then did nothing but spam CYDSTEPP.