I’m pretty new to magic and whenever I think I know what’s going on I usually don’t. Here is the situation thanks in advance!

Assuming a card like Jokulmorder comes into play and has the text: “comes into play tapped” and “Doesn’t untap during your untap step” and “whenever you play an island, you may untap” to paraphrase.

My question is can you use a creature ability to untap a card like that without meeting the conditions?

I’m pretty new to magic and whenever I think I know what’s going on I usually don’t. Here is the situation thanks in advance!

Assuming a card like Jokulmorder comes into play and has the text: “comes into play tapped” and “Doesn’t untap during your untap step” and “whenever you play an island, you may untap” to paraphrase.

My question is can you use a creature ability to untap a card like that without meeting the conditions?