Inspired by jmgariepy's comment on Shefet, The Endless Dunes

I'd prefer positive synergy with Deserts.

The positive synergy is that it can't be targeted by opponents' deserts and can use them to be unblockable

That's not positive synergy. On the contrary, because this is detrimental to playing Deserts, you want to play less Deserts with this around.

Not everything that's not a drawback is automatically positive synergy.

­Shefet Monitor is an example of positive synergy since it becomes better with Deserts around and Deserts become better with it around.

Isn't there like 1 desert that can negatively target a creature? And 1 that can positively target one?

I count four that negatively target and two that positively target, but I just gave it a quick glance and might have missed some.

There was only one back when we got Camel though.

All Deserts though get punished by Desertwalk.