What were the desires that lead to the Euphorics' powers? For some of the characters, it was quite obvious what their desires were:


Saiga's desire to capture life in his camera
Katsuya Shirogane's desire to be as flexible as rubber
Kamiya's desire for food.


However, for others, it's not so obvious:


Father Kanda had the power to control lighting, but it's not clear why.
Ran Yurigaoka's power to make his tattoos come to life seems to conflict with his pride of having perfect skin.


What desire did each of the Euphorics have that allowed their powers to manifest?
As @Hakase has mentioned, Father Kanada's power is likely to be based on his religious beliefs. A lot of religious texts - biblical or no, mention smiting which is usually portrayed as lightning.

As for Ran Yurigaoka's power, A common phrase among tattoo artists is that skin is a canvas . With his obsession with skin, he probably considers it art in a way also - and tattoos a further extension of that.

Most likely though, the character designers simply thought that these powers would be the most impressive for the personas they had, and there wasn't significant deliberating on the preciseness of the connections.