They're practically a female version of Sonic and Tails, well except for Blaze being so serious and Marine being a jabbermouth XD.
Called it "Sol Duo" cause they both hail from the other world paralle to Mobius (called the Sol Dimension sometimes in the comics). People tend to forget that Marine can use a special power seen at the end of Rush Adventure. She's most likely hydrokinetic do to her large affliction with water and her name is "Marine".
Anyway, these two are perfect teamates.
marine: ohh sonic, blaze *water ball apear above her hand*
sonic: *gulp*
blaze: *gulp gulp*
knuckles: *gulp gulp gu-*
sonic: shut up knuckles
knuckles: *country voice* run bitches run
sonic and blaze: *runs away like hell is chasing them*
... Which makes the pairings of Sonic/Blaze and Tails/Marine quite disturbing, when you think about it... More so than other Tails pairings, which are disturbing enough to me as it is...