It adds a new dimension to the Sonic fandom. It gives fans a different way to explore the relationships between characters. For those who love Sonic and Blaze, it satisfies their desire to see them in a romantic context. It also encourages creativity among fans as they write and share these fanfictions.
Tails would be the first one to come to Sonic's aid. His intelligence and flying ability would be very useful in finding Sonic and getting past Eggman's defenses.
Well, usually in these fanfictions, Tails meets Sonic during an adventure where they both end up at the same place by a series of coincidences. Their meeting leads to an exciting partnership.
In many Sonic Boom fanfictions, Tails often meets Sonic by chance during one of Sonic's adventures. Maybe Sonic is in trouble and Tails shows up to help.
It's hard to say whether the 'amy kills sonic fanfic' is popular. The Sonic fanfic community is diverse, with fans having different tastes. Some might enjoy exploring the darker and more controversial storylines like this one, but it could also be that a large portion of the community prefers the more traditional, positive stories. So it might not be as mainstream popular as some of the more typical Sonic fanfics.
One common theme is the discovery of love. Often, Sonic and Amy start off as friends or at least comrades, and through their shared experiences, they come to realize their deeper feelings for each other, which leads to the kiss.
The Sonic comics are good for several reasons. The action is intense, the humor is spot-on, and they manage to keep fans of the franchise engaged and entertained.