Shapesharer is a creature (shapeshifter) with changeling (this card is every creature type at all times) that, for 2U, states "Target Shapeshifter becomes a copy of target creature until your next turn."
This makes me wonder several things.
Say you have Coat of Arms in play. Coat of Arms says "each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it". So let's say you have two Shapesharer's in play. Shapesharer A gets +1/+1 because it shares the sliver type with Shapesharer B, it gets +1/+1 because it shares the elf type with Shapesharer B, +1/+1 because it shares dragon type, etc. So it seems two Shapesharer's in play with a Coat of Arms could make each one have infinite power and toughness? Of course if that's the case than it seems like Shapesharer's would each also simultaneously be Legends and kill each other.
Say you cast a creature and that creature has summoning sickness. It seems like Shapesharer could copy that creature and that the summoning sickness wouldn't copy over so you could use that creatures abilities on the turn it was cast, albeit with a different creature. Is that correct?
Does Shapesharer still retain the Changeling ability after it's copied another creature?