Watch it again. CSK doesn't make the water stop flowing. He lifts a bunch of it when he got summoned. Then it dropped when he disappeared. This doesn't imply time manipulation. This is really no different than when characters break the ground and cause rocks to float with their MP.In the anime, water did stop flowing, Just rewatched it.
My point is that God Slaying magic is far superior to Dragon Slaying magic. The nature of the magic is completely different, with God's magic being superior. This suggests that Gods being superior to Dragons is the norm, not the exception.
We only know of one God in it's true power, Ankhseram. He can solo the verse in an instant if he wishes to. Your judgement is based on other two.
- Dimaria's was a takeover, and the power of the takeover depends on the MP of the user, see how Satan Soul's power changed over the series as Mira herself improved.
- Second one was a summoning, whose power depends on the summoner, and Arlock was weak. In fact, if we factor in his (and his guild's) weak MP and see how strong Ikatsunagi was (no sold base Natsu's attack) inspite of the weak summoners, it's logical to assume that the real Ikatsunagi is an absolute monster of a powerhouse.
How is god slaying magic superior to dragon slaying magic? Half of the dragon slayers in the series can solo the 3 god slayers that we know of. The only advantage that a god slayer has against a dragon slayer is that their elements can't be eaten without emptying out your MP reserves. This is useless if your elements are not the same.
Ankhseram is the outlier here. We've seen Chronos fight and we've seen Ikusatsunagi fight, but we don't know anything about Ankhseram. Dimaria literally has Chronos' Soul, which means she has access to all of her powers. MP might affect how long she can sustain the takeover, but that was never really an issue in the first place.
Again, that's not how summoning works. We know for a fact that stuff like Lucy's spirits have their own magic power that is irrespective of the summoner. When Loke's first owner died, Loke kept himself in the human world with his own MP. Having summoner lessens the burden of keeping the gates open and also makes the spirit stronger, but the spirits have a baseline stat that they simply cannot fall below. No matter how weak Loke's summoner is, he cannot get weaker than when he's keeping himself summoned. Ikusatsunagi, if he works anything like Lucy's spirits, will have his own baseline stats. If he tries to summon himself to the human world, he would be even less powerful than when Arlock summoned him.


