Replacing a creature counting as a kill and not as an exile.

Gunmix25

In the Trial of Strength, I replaced a weakened creature on the battlefield with one cast from my and was double checking the objectives and noticed that the replaced creature was recorded as a kill against me and not as an exiled creature. Shortly after that I tried to see if I could recall it via 2nd Loyalty with Lill 3 and it was not in my graveyard; telling me that it was exiled as normal.