Becoming a devil is a temporary decision, its called Dragon's Ascent for a reason. Becoming one at the moment gives him advantages such as demonic power and evil piece boost that he study and replicate later on when he decides to change race again.

He is gaining a Satan class bodyguard, servant and on demand Ultimate Class ingredient dispenser.

Shiro does not own the plot point of making Grayfia a servant and he wasn't the first to do it either.

It was decided through a poll, besides I had a different DxD fic where mc didn't join a peerage. Though I will try my best to take a unique spin on the peerage formula.

Killing his sisters's semi boyfriend she would fight for who is deeply related to the Grigori is not a great Idea, and even if he can kill a Juggernaut drive it would no doubt decimate the country. Also even if Azazel wants peace killing his revolutionary alchemist friend would not go over well with him at all, much much less so with the other Grigori members that know about Takumi from the potions he gave Azazel.

All of DxD if I can. No plans of dropping it anytime soon,

Akira barely did alchemy, he did not get to use the sacred gear nor did he join the Gremory peerage. Are you sure you read Necromantic?

Is that hard on for joining Rias in the room with us right now? Because from what I remember I wrote an entire fanfiction where mc didn't join Rias and left it up to readers to decide this time. And so far Takumi has not made a single decision that has harmed him meaningfully.

That's why he set that time to make it seem like he doesn't know what he is doing. The entire story line of DxD isn't more than 2 years, and Sirzechs leaves to fight Trihexa by then.

It would hurt about as much as an acorn falling off of a tree would.

He needs to learn how to first.

He already has the bodies it's the other things that are problematic.

How is he pathetic? Of course he is going to rely on potions he is an alchemist. He is still a human dealing with the issues of a human but that won't be for long.

Give only to man, sperm too powerful to fuse properly with the egg. Give only to woman the egg is too strong to get properly seeded by the sperm.

The milk doesn't increase fertility, it possesses an alchemic value that does, you can find a better explanation of those in the earlier chapters.

Way ahead of you

emphasis on giant. It is fast and large, and earth transmutation is not particularly fast.

He did not scare the other pantheons into submission, he would be around or less than Shiva in strength which is nothing to scoff at. He couldn't wipe the entire race by himself since the og Satan's were at least somewhat cracked, He didn't die to single god either, it took all og Satan's working together to put him down. And again, no concrete numbers, we just know he over exerted himself sealing 666 away.

It is fannon, this is DxD we never get concrete numbers or basically details to anything. All that is confirmed is GOB sealed 666 and got weaker because of it, dying in the great war as a result.