after first battle with alduin and you talk to the big P dragon , he shows these words and you can meditate on them (it seems repeatable also). are these doing anything to increase character's ability or are the just asthetic? thanks

They are additional permanent effects, you can only have one active at a time:

Fus (Effortless Power): The probability that you will be pushed back by enemy attacks falls by 25%, while your attacks cause 25% more on the opponents.
Feim (Eternal Spirit): In ethereal form your health regenerates 25% faster.
Yol (The Inner Fire): Fire-Breathing scream causes 25% more damage.

EDIT: specified the effects

It′s the award for not killing Paarthurnax. If you choose to do the Blades' bidding and kill him, you get a perk that reduces 25% of melee damage done by dragons (perk currently bugged and not working).

If you kill him after having received one of the meditation effects, it will stay active plus you gain the Blades' perk.

Both the meditation and the perk can be gained before Blades tell you to kill P.