Deus could conjure thousands of bone spears with just a wave of his hand. He was well aware that the attack power and durability of those bone spears wouldn't be much use against opponents that were stronger than him by a large margin.
After all, it was an area of effect attack that Deus had developed that was mostly used for wiping out a group of cannon fodders. It could also be used for opponents with the same power level as his bone manipulation but what Deus needed was stronger attacks than that.
He wanted to develop the same attack but much more sharper and durable with faster trajectory speed. He wanted to create stronger bone spears but still retain the quantity of a thousand.
Only by creating an attack like that would he be able to make his opponent lose hope in fighting against him. After all, having an attack with stronger attack power than the opponent but also having a numerical advantage would make anyone who faced him lose hope in fighting against him.
