First off, tapping for a colorless mana is pretty flavorful for a desert
But even treating this as a 4-mana 3/2 that draws you a card sounds really good, and you can obviously divide up when you cast the two halves to make it feel even better and if you always have the mana available when it dies, it will just keep coming back When it has a big enough friend around, it is going to be an intimidating attacker on any board and that alone is enough for the Ruiner to be relevant almost all game long
The idea of using essentially the Magic version of the Death Star to throw 100 damage at a lowly creature only to somehow win the game as a result is just too hilarious to pass up
This creature doubles all your mana dorks and will help you buff up your entire army, giving elves a boost it absolutely did not need
However, Pendulums have still had competitive builds since the nerfs to their mechanic and remain potentially dangerous given the right support
Doubling Season doesnt have a Golgari watermark but it was first introduced in Ravnica: City of Guilds and it plays well Golgari +1/+1 counters as well as Saprolings, so Im okay with Golgari adopting the card as our own