dnd 3.5e – Spellthief vs Spellthief

Suppose we have a spell stealer with a spell-like ability to steal (see here) and a willing creature, such as a unicorn, from which the spell stealer wants to steal a single spell ability once per day (for example, to heal moderate wounds) that the consenting creature has not used yet. Assuming that the consenting creature never uses its spell ability once a day, is it possible for the spell stealer to steal and use that ability more than once a day?

In my opinion, the arguments in favor are the following:

  • The description of the capacity says "A spell thief can use a stolen ability similar to a spell once"

  • Spellthief sucks, so a permissive MJ could allow it regardless of RAW.

As to the arguments against:

  • Descriptions says For all intents and purposes (caster level, hard disk backup, etc.), treat the spell-like ability as if it were used by the original capacity holder. and it can be argued that this may include not being able to use spell-like ability twice a day, or even preventing the consenting creature from using that ability after the Spellthief l ' Used (considering that it counts as a creature having launched).
  • It sounds terribly exploitable, so a GM can decide it independently of RAW.