OK, I have finished the book, and still do not understand why Silchas Ruin did the walking thing, other than perhaps having an urge to help out Seren and Udinaas. And again, seems like he could have just (gently) grabbed those two and Kettle in his claws and flown away.
I also hate how marines with cusers can so easily defeat him towards the end of the book.
I know one of the main themes of the Malazan series is that things evolve and get more powerful - but seems like an ancient god could have put up a better fight against Quick Ben and marines with cusers than the thre sisters and Silchas Ruin did.
Still go down to the humans in accordance with the series theme - but still able to put up a better fight than that.