Decaying Hex not inherited through Blasphemy, Hex Bloom

The support gem Decaying Hex's effect is for the "supporting skills" to inflict a Chaos DoT for the curse's duration. Despite this, Decaying Hex does not actually alter the curse it's attached to, but rather places a separate Decaying Hex debuff alongside the initial cast. This means that if a skill containing Decaying Hex is applied to a target through any other means, such as Hex Bloom or Blasphemy, Decaying Hex does not take effect.

This quirk also means Decaying Hex remains active so long as there is a curse on the target, even if it's not the skill that Decaying Hex was supporting. This means that if a character is running an aura curse via Blasphemy, a character (not necessarily the same one) can cast Decaying Hex for an effectively infinite-duration DoT even if the curse itself is applied and removed in the same frame.

The more reliable, versatile implementation would seem to be to attach Decaying Hex to the curse it's supporting. (Or likely the first slotted curse, in the case of Blasphemy.) Anything which spreads the curse should also spread Decaying Hex, and Decaying Hex's duration should be tied to that one specific curse rather than all curses. This both makes it compatible with Hex Bloom and Blasphemy, while also preventing easy access to infinite-duration DoTs.