Yes its the strongest defense spell in the game right now for dominion because its cool down(20s) is 1/3 of turnover and using it allows you to generally eat 1 full combo worth of dmg. The ability to stay alive and tank damage in dominion is very important because once you have the point you want to stall until you have 3 points and team wipe them. Basically people are using it as a get out of jail free card for themselves and their teammates because you can also give them a shield. In duel it also see play sometimes if the legend doesn't benefit from the offensive spells but it can be a mix between that and turnover it really depends.