
Originally Posted by
Cleretic
No given reason, but personally, I suspect it to be that he outsmarted Eureka and its weapon.
Consider that all of Eureka's created weapon-primals (except for Proto-Ozma, which is weird) have a wielder with a fitting personality; the wielder becomes the mythical bearer of this blade. Indeed Odin is according to some lore an actual myth from somewhere in the north. So it's a bit of a 'Jane Foster as Thor' situation.
But I don't think Ejika thought like that. He wasn't asking for 'a sword worthy of Odin' or something like that, because he doesn't think that way. He would've just gone 'give me a real good sword'. And if you do that... what would a primal that's just 'a real good sword' even temper you to do, really? Would it just temper you with a desire to swing it at something?
I think Ejika realized that. He realized that even if that blade would be dangerous in the long term, an effective 'blank slate' primal would do the job right now. After all, the most it would want from him would be 'kill something', and... well, look what they actually did with the thing!
EDIT: It's either that, or just the simple notion that a Eureka weapon tempering takes some time, it isn't instant. Which does seem to be the general depiction given to Odin; if it were instant then it would just be an unbroken chain of 'people grab it and then they're Odin', while in its storyline someone does run away with it (thus implying at least a brief 'not being Odin' period), and the FATE taking a few days to respawn does suggest that it takes some time to really consume the wielder. If Ejika knew that, and knew he at least had a couple minutes before he was gone, that'd explain his plan. He doesn't need a lot of time; just enough time to throw a sword.