>>724020314
You're not at all reading what I posted. You just looked at 2 keywords and made an assumption.
When you're using Spell Echo, you can Blade Blast in the middle of it to have only the last cast on-field. If you specifically use Greater Spell Echo from Pledge of Hands, which gives 2 Repeats and grants 30% More damage and 50% Increased AoE per repeat, you can snapshot a BV with 60% More damage and 100% Increased AoE by cancelling the first 2 stacks with Blade Blast. Additional stacks will retain this bonus until the whole stack is lost.
Of course, you're using a Pledge of Hands, which means you don't get your normal weapon bonuses, but Unleash functions the same way for this information.
So as a result, BV can't gain the % More damage from Oshabi Owl ascend's Unleash effect. You'd just get the extra casts.