Abaddon was fully reluctant to open the doors to Oblivion for several reasons.
His primary concern was Yesh.
Oblivion's powers were what had put the old man in his current predicament in the first place.
Would further use make them worse? He didn't want to be responsible for the death of the old man.
Furthermore, Abaddon abhorred the idea of messing with the timeline again.
When he put people in Oblivion via the gates, the next time that he slept, he would unconsciously rewrite reality and create a timeline without whoever he'd shoved in there.
The first and only time he did this, he ended up with Sif as an ex-wife and Thrudd as a daughter.
Those were happy accidents. He had no wish to change them.
And yet, he was iron-clad in his resolve not to make those kinds of mistakes again.
But with the introduction of his family into the battle, Abaddon was out of time, and he was out of options.
The Ophanim wouldn't be passive forever.
