Use "Safe Zone" to protect this card from being targeted by effects that would remove it from the field without sending it to the Graveyard. Also, if your "Safe Zone" leaves the field and destroys "Guardian Dreadscythe", "Guardian Dreadscythe" will bring itself back with its own effect.
Use "Ectoplasmer" to Tribute to inflict 1250 damage, then get it right back by discarding a card.
Use the effect of "Inzektor Exa-Beetle" to equip this card to it, then use its other effect to send this card and one of your opponent's cards to the Graveyard, letting you Summon this card with its own effect.
Having multiple copies of "Reaper Scythe - Dreadscythe" in your deck can allow this card to regain its attack power if destroyed or equip this card with more than one "Reaper Scythe - Dreadscythe" to boost its attack even higher.