Zurin Arctus, Underking

When Zurin Arctus enters the battlefield, create a Mantella artifact token with a lifeforce counter
on it. As long as you control an artifact with a
lifeforce counter on it, Zurin Arctus is hexproof
and indestructible. Only one artifact may have a lifeforce counter on it at a time.
{5}{t}: Put a lifeforce counter on target artifact you control.
Zurin Arctus, Underking's power and toughness
are equal to the mana value of artifact
you control with a lifeforce counter on it.