Haste
Whenever you cast a spell that targets Tenth District Legionnaire, put a +1/+1 counter on Tenth District Legionnaire, then scry 1.
Tenth District Legionnaire’s ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
You scry 1 even if you can’t put a +1/+1 counter on Tenth District Legionnaire, most likely because it has left the battlefield.