Why was dracula holding back?

[Shin Dan]

Now, not sure if you guys noticed this, but during the events of MoF when alucard and simon team up to fight dracula, drac never once uses his void or chaos powers.
Now when trevor fights him, he uses them up until the final cutscene, then he switches back to the blood whip and a hellfire version of his blood fireballs when he's falling to the mirror room.
the question I have is, did he hold back against alucard deliberately, or did trevor do something to weaken him in the past that prevented him from using void and chaos magic?
Many like to think that dracula, unwilling to harm his son, just naturally held back, but...
what if trevor's combat cross had indeed weakened his power in the past? what if he had no immediate method to regain his full powers? could it be that the combat cross in its unweakened state had actually had some small effect on dracula? it did seem to have power in it back then, though later it was no better than a common whip in simon's hands, it doesn't even hurt dracula as much, though it still staggers him.
Could trevor's whip have disabled his void and chaos magic and trevor just ran afoul of good fortune? or was dracula truly holding back and was unwilling to reveal that fact?

[commander]

Yeah when he was fighting trevor, he didn't know it was his son and didn't hold back, only until he became alucard then dracula held back on both alucard and simon, although as you mentioned about his weakened power, I noticed something similar in this situation where they said in Mirror of Fate, at the moment simon finds the combat cross that trevor used, it says the combat cross is weakened over time after being used alot from previous battles or something similar that I can't remember, but it still has the ability to grab enemies and be a grappling hook for those high places to swing and climb.

Which means both dracula and the combat cross are weakened, so let us have a weakened vampire fight? lol sorry ironic, I could just see dracula getting pushed and falling over with an ugh sound.

[-★- sevenfoodsandwich -★-]

I think he was trying to get in his mind and defeat him mentally, rather than physically. He kept telling him to give in to his anger and release his true power, and he turned Simon against Alucard, trying to get him to attack Simon.