Does Ana's ult carry over to an ejecting DVa?
No. Switching from mecha to mech-less (and vice versa) will cause the buff to be wasted.
This means you lose the buff in three ways:
- Mecha D.Va is powered up and then the mech is destroyed by an enemy
- Mecha D.Va is powered up and then she uses her ult (mech is destroyed)
- Mech-less D.Va is powered up and she calls her mech back
Source: I play Ana and it tilts me to no end when I boost a D.Va and she immediately decides to ult.
No. If her mech is killed, or she uses her ultimate ability, Ana's Nano Boost is removed. The opposite also applies: If she calls her mech while boosted, she does not keep the buff.