Your last chapter was frankly incredible. New insights were given to us using the same events and scenarios and that kind of flexible mind will usually always allow for a unique story. The only thing I will forewarn you about is that most readers, myself included, will be expecting a lot of focus to be placed on Shirou as he is the sole representative of the other crossover FSN so we don't want him to be marginalized.

As for the power levels? I'm assuming you have him set at a solid C across the table for now and for some that will be far too weak or far too strong. You can tell these people that their opinion doesn't really matter and as long as you're consistent with the depiction of his abilities then you will receive on complaints from me. Issei went from the weakest possible reincarnated devil to a god slayer in less than a year while Shirou has already slain half, three quarter and full on divine beings so yeah, the dude deserves some cred and the amount depends on how big anyone who knows the series values his contributions which is always variable.

The only thing I would like to see is more FSN characters, particularly an over enthusiastic Rin salivating over the magical knowledge of the Underworld and gnashing at the teeth to get Shirou back into her harem from Leviathan. I really want to see Shirou back in his/Rin's all female harem with the sole exception of him but that's because I have find memories of the group interactions. But hey, once again, you have a great story going on and as long as you continue to exercise this creative writing than I'll continue to be a fan.

i suggest that serafall will complete her 'ultimate peerage' consisting heroes like arturia and lancelot as knights, iskandar and heracles as rooks, medea as a bishop and the two lancers that i forgot the name and medusa as pawns. a colllection of heroes from the 'throne' serving serafall.

The cliche of being turned into pawns was because of people starting from cannon and either picking sona or rias's peerages to be the focal point mate... and for the most part in regards to the power levels the pawn and multiple at that were the only pieces that could be a choice.
But enough of Cliches Amazing story and even more amazing the fact that another person (A total of three now as far as I have seen) using Serafall as the king of (Insert crossover/OC character here)

Continue, your story have a great deal of potential

i'm really loving this story and i'm hooked!

Continue the story please your have me hooked.

Ho? Giving Serafall a peerage...or at least Shirou? An interesting concept with quite a bit of potential. I look forward to the next one

That was awesome!

Aside from a few missing words, this story has definitely been an enjoyable read so far. I love how you're doing something completely different than most DxD crossovers. I'll be keeping a close eye on this one for sure. Keep it up!

very interesting...

I do like the way this is going, but Question but what about Illyasviel where is she? I mean he did just sell his soul to save her but she is nowhere around?