Keyword Slay is the new unique keyword in TES:Legends. If your creature with this keyword destroy opponent’s one on your turn the bonus of keyword Slay will be activated. This bonus is unique for every card. The bonus effects of this keyword looks perfect when you control the board. It can give some buffs for your creatures like bonus +1/+1 of
There is some creatures that had a bonus effect, which later became a keyword Slay for them (Pahmar-raht Renegade now has another description with keyword Slay). Also there is a Support card
The cards with keyword Slay are very strong on Arena because you should control the board there and you will get bonuses after slaying creatures of your opponent. For this reason you will not see this keyword in aggressive decks now.
In control decks the cards with this keyword are pretty strong.
You can build good midrange decks with creatures that have keyword Slay because it is very important to do good trades in this decks. You can also use the powerful legendary creature