aHEM!
Let's start battlewise. Both the Murkwood Enderling's and the Darkspine Enderling's synergies consist of one type, Assailant for Murkwood and Rogue for Darkspine. While many would argue that Assailant is better for combat, the only boost you get out of it is damage that caps out at 40%. Rogue, on the other hand, gives you two boosts, prioritizing backline enemies and gaining critical strike chance. So let us paint a picture, imagine a 1v1 between a Murkwood Enderling vs Darkspine Enderling. The Murkwood Enderling has the high ground with attack and speed, but since it's one synergy short, it doesn't get the extra 20% damage boost. The Darkpine Enderling has one up on the Murkwood Enderling in HP, defense, and, oh yeah, DODGE. While you could say it depends on the RNG, you're forgetting one thing, the Murkwood Enderling's primary attack is charge. And if you can recall, charge only does 50% damage. So with higher HP, defense, and the 20% extra dodge, the Darkspine Enderline would of course reign victorious.
Now, let's switch topics and move on to colorwise. Of course, most people would argue that color isn't important, or that it's just for the 'aesthetic'. But no, it goes a lot deeper than just what's on the surface. Other than too much red causing visual strain, it's a color that's associated with an equal mix of positive and negative connotations. Its positives include strength, power, love, and courage, which all sound fine and dandy until we get the negatives. Rage, danger, defiance, and stress, they're all associated with the color red. The color purple, however, has more positive connotations than negative. While, yes, it does have its negatives such as representing sadness or frustration, its positive connotations include luxury, power, nobility, relaxation, stability, creativity, and even mystery.
With all that said, I firmly believe that the Darkspine Enderline is superior to the Murkwood Enderling. Thank you for your time.