Ghostly Flicker gets you two targets for 3 mana, a sweet deal
Outside of that, it triggers on enters the battlefield, so repeated flickering could net you additional cards
Like most Magic: The Gathering cards, the value of Green Sun's Twilight depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Phyrexia: All Will Be One)
There are lots of ways to give creatures Shield counters which function as one-off indestructibles that fall off the creature if it takes any damage or would be destroyed
In exchange, the player can search for two more Grubbin and put these on the bench
He is a lord who is kind to the non-paying force