So while i was fighting in faerina's shrine, i noticed that come sylestis had rarities, does this affect anything other then it's harder to catch rarer sylesti?

Rarities, indicated by color of the stars, tell you about the amout of trait points the sylesti will have.

White - Common - No trait points
Green - Uncommon - 1 trait point = 1 carried trait
Blue - Rare - 2 trait points = 1 visible trait OR 2 carried traits
Purple - Epic - 4 trait points = 2 visible traits OR 1 visible+2carried OR 4 carried traits
Orange - Legendary - 6 trait points = 3 visible OR 6 carried OR a combination of visibles and carries

There are also Red - Mythical but I do not remember their exact trait points count right now.

Oh, ok. Thank you!

No problem :)

Also... A little advice for the future ;)

When you answer to someone's post, you can ping them by clicking the blue @
in the lower right corner of their post. Like I did just now :)

Then that person will be automatically informed of the ping
and they can see your answer easier. ^^
That's extremely usefull in a thread where multiple peaople talk.

oh, that's handy! thanks for telling me

You're welcome! ^-^