Elder White Dragon

Flying, lifelink, indestructible, hexproof for {x} turns
When Elderly White Dragon enters the battlefield, it exiles target permanent for {x} turns. This cannot be countered or blocked by hexproof.
{x}{p/b}{t}, add {x} to exile counter.
When Elderly White Dragon attacks, it can defend against {x} creatures with reach, and gets {x} +1/+0 modifiers and gains hexproof for {x} for turns
When Elderly White Dragon blocks, it can only block {x} flying creatures, and it gets {x} +0/+1