Cannot be Normal Summoned/Set. Must be Special Summoned (from your hand) by having exactly 5 DARK monsters in your GY. If this card is Special Summoned: Add 1 monster with 1500 or less ATK from your Deck to your hand. You can only use this effect of "Umbramirage the Elemental Lord" once per turn. If this face-up card leaves the field, skip the Battle Phase of your next turn.
Sangan doesnt win games like this guy. Try 3 kuribohs 1 snipe hunter, and 1 great maju garzett in a deck with last gamble. When discarding for kuribohs eff you can discard as many as you want during 1 damage step to fulfil your gy needs.
You can probably load the graveyard with dark crusader to help fulfil this card's summoning condition