I'd say keep Sylys in, having become a recent convert to the eSorscha + Sylys combination. Being able to make a whole unit stationary while still having enough focus to Cyclone back to safety is simply amazing! A 16 inch threat on shutting down whole units for a turn while staying safe is really harsh! And once you've hit them once, they can't get out the way for next turn
In your list, I'd look at using that to shutdown the inevitable one bodyguard unit, which will most likely be the only non support models except the stormwall and caster in a 35pt list. Shutting down that percentage of an armies offensive output would be excellent!
Cheers,
Dave