So i beat the dlc and went to fight Sif. after dat cool cutscene we started fighting, and i feel like he was slower and not as powerful. am i crazy,*SPOILERZ* or does he go easier on you after summoning him to beat Manus?
If you summon Sif in Oolacille and beat Manus before coming back to the garden in the "normal game", you actually trigger a different cutscene to start with:
Sif immobilizes you on the ground under his paw, smells you and howls as his recognizes you and goes visibly reluctantly to fight you after this instead of the usual growling-grabbing sword-fighting stance.
So it would absolutely make sense that he would be easier on the player if you already "freed" Artorias in the past since he would then remember you and would reluctantly fight his master's "savior".