Cuz Remember Delta originally was for multi targeting, but I had to change it because there wasn't a mechanism for it.
You misunderstood. Multitargeting has potential for known exploits. The exploit was clicking a target and then clicking cancel before it disappeared. (Since removed by decreasing the time it took for cancel to disappear.) Multitargeting would enable this exploit again.
Usually good card ideas either introduce a new mechanism or a new implementation of an old mechanism.
PS: Discard targets a card in your hand. Same mechanism can be applied for the opponent's hand.