Also
v11.1 p15 ~35%
After the time I’d sent the Craving Blade off with my space-time magic, only for it to return and burn me, I realized that I would need to deal with the lingering heat. I had used it to my advantage this time and completely incinerated the enemy.
I don't remember the Craving Blade ever burning him after being transported elsewhere, back in volume 3 after he sent it off it later just reappeared by his bedside in volume 4.1, with no heat or burning involved.
Checking the source
過去に渇望の剣を空間遷移にて吹き飛ばしたが帰ってこられた反省より、熱で念入りに焼いた後に余熱の処理をかねて放逐する術式は正しく敵を消し飛ばした。
which is something vaguely to the effect of "having learned from the time when I sent the Craving Blade away with space-bending only for it to return, the spell now completely incinerates the enemy and then banishes it to deal with the residual heat, obliterating it entirely."
which would be more consistent with the events of those volumes.
It's also more consistent with what he describes himself as doing here, where the space bending is a way to dump both the enemy and the lingering heat, not the source of heat (that was the fusion reaction).