Nautilus, Titan of the depths

Untap Nautilus at the beginning of your end step.
{2}{g}{t}:Dredgeline; Fight target creature.
{g}:Titan's Wrath;Prevent 3 damage on Nautilus
until end of turn.(activates once per turn.)
{1}{u}:Riptide; Deal 1 damage to Dredgelined target
and adjacent creatures, tap them.(once per turn.)
{2}{u}{b}:Deal 2 damage to target creature.If that creature is Dredgelined, repeat this to adjacent targets.
creatures damaged by this ability don't untap during