What were the desires that lead to the Euphorics' powers?
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.