Not sure I understand what you mean by a "one-shot" deal for Special Initiative. By the last paragraph of the Reg, it stipulates that in the right circumstances a "separate" instance of Special Initiative is triggered, but at the beginning of the paragraph it suggests that Special Initiative only occurs once per "completion" of the opponent's ability. The way I'm reading this ruling is that Special Initiative can occur multiple times as long as the opponent's ability is not completed. If a removing effect is negated, and then this negate is undone, this would trigger and grant the losing player a separate instance of Special Initiative per the last sentence of the Reg. If a triggering of a separate instance of Special Initiative is generated, then the removal ability is then, once again, suspended, leaving it incomplete, thus potentially creating a loop of Special Initiative until the losing player cannot respond to the removal or the player playing the removal ability is unable to undo a negation/interruption of the removal ability.
If I am way off base, could someone please clarify, because the way Special Initiative is written would seem to suggest that "separate" instances of Special Initiative can occur apart from the triggering of the original Special Initiative instance.
"This only occurs once per completion of an effect of an opponent’s ability. If a removing effect is negated (or cannot reactivate after an interrupt effect is played) and the negate (or interrupt effect that prevented reactivation) is later undone such that the original removing effect reactivates, this would trigger a separate instance of Special Initiative."
