Marjhan doesn't untap during your untap step.
, Sacrifice a creature: Untap Marjhan. Activate this ability only during your upkeep.
Marjhan can't attack unless defending player controls an Island.
: Marjhan gets -1/-0 until end of turn and deals 1 damage to target attacking creature without flying.
When you control no Islands, sacrifice Marjhan.
5/1/2008 The ability that untaps it during your upkeep has been returned to an activated ability. There is no restriction on how many times it can be untapped during your upkeep with this ability.