If you have 3 or more "Destiny HERO" monsters in your Graveyard: You can discard this card, then target 1 "Destiny HERO" monster in your Graveyard; Special Summon it to your opponent's field in Defense Position. Negate any Spell Cards or effects you activate, and if you do, destroy that card. During your Standby Phase: You can banish this card and 1 "Destiny HERO" monster from your Graveyard; each player chooses 1 Normal Spell Card from their Deck and places it on top of their Deck.
It can target itself, but there has to be a legal target in there to activate its effect. (Which there usually will be, but you could have been a weirdo and discarded 3 Destiny HERO - Dogma as the only D-HEROes in your GY or something.)
It’s good for negating opponents spell cards but the problem here is they can also be used for their tribute summon right?
Blame the anime and their situational cards and Konami printing a lot of GX cards in a stupid way.
As written in YGO Wikia, in anime, this card was specially designed to take down "Destiny Hero - Plasma", according to Aster Phoenix. It defeats "Plasma" by changing the top card of the opponent's Deck, which is where "D - Force" would be present. In the anime, this negated the effects of "Plasma".
It was released in the ARC-V era in the TCG/OCG, but it appeared in the GX anime. (Same goes for Celestial.) He never used it in ARC-V, either. (Actually, aside from Polymerization, ALL the cards Aster used were new in ARC-V, unlike Alexis, Crow and Jack.)