This is a very effective spell that would have been extremely useful even if it wasn't a shield trigger. Being a shield trigger makes it even better.
Since it's cheap it need not be exclusively used as a shield trigger.
It can be used on your creatures as well as an opponents creatures giving the user an advantage either way if played right.
Strategies and game play:
This card can be used to summon any creature one turn earlier by swapping a creature in the battle zone.
Can also be used to summon high cost creatures that were put into the mana zone at initial stages of the game.
Swapping opponent's creatures with weaker creatures or creatures with abilities advantageous to the user/
Combos with other cards:
It is very popular as a combo with Bombazar or Bolmetheus. It is a very deadly combo as there is not a lot the opponent can do about it.
Ways to counteract it:
One way to counteract this card is to use the same card against it.
Low Mana. Shield Trigger. Can be used to Attack or Defend.
It requires a creature in the battle zone.
Artwork and aesthetics:
The artwork is vague and you can make out a sort of shaman working on a soul swapping spell apparently.