I think that's a good idea.
Something like this?
Paradox (Su): Instead of using its energy drain, a temporal stalker may choose to instead alter one aspect of the victim's past made within the last 24 hours. For example, the stalker could swap out one of a wizard or cleric's prepared spells for one less useful in the current battle. Or it could have the victim choose to bring along a flask of acid rather than a vial of holy water. A successful DC X Will? (Fortitude?) save negates this effect. The save DC is Charisma-based.
Just thinking about paradox: maybe we should state that it can't be used to deal direct hp damage (ie, changing whether they got hit once more in a previous fight). Or should we let it do that?
(Psion/Wilder 2, Medium Range, Will Save for half damage)
The fabric of time parts to your will, revealing wounds your foe has received in the past (or has yet to receive). That foe takes 2d6javascript:void(0); points of damage as the past (or future) impinges briefly on the present.
Create spawn should only work when the character is killed by energy drain (per original text).
I like Cleon's skill suggestions. If we wanted to make them actually use their spellcraft, we could require their paradox feature to make a Spellcraft check to be able to choose what spell the victim prepared instead, otherwise it's random.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.