If you feel people keep playing the same few cards over and over again, why not start by including some of these lesser known and lesser played cards in your own decks yourself
The monarch mechanic from Conspiracy: Take the Crown encouraged attacking, but it also helps spread around ways to draw an extra card or three
If each target card is an illegal target by the time Lochmere Serpent's last ability resolves, the entire ability won't resolve
On top of all of that, it is a one mana 1/1 with Menace, a creature that can attack fairly effectively in the early game, and which can pump itself with its ability, so if you have the ability to give it death touch, youll be taking down two things no matter how your opponent blocks
1 Rampant Growth
What makes the card so strong is that its great at bridging the gap between your mana development and your win conditions