No, it cannot be tributed. If the player attempts to apply the effect of "Monarchs Stormforth" on a monster unaffected by Spell Card effects, then they cannot attempt to tribute again using the same effect of "Monarchs Stormforth".

No, it cannot be tributed. If the player attempts to apply the effect of "Monarchs Stormforth" on an opponent's monster, it has to be on a monster that can be affected.