What's the number on Lucios HUD?
Solution 1:
The number lets you know how many of your teammates (other than yourself) are under the effect of your AoE heal/movement buff. For example, if the number is '5', the whole team is receiving your heals/boosts. If nobody (other than you) is receiving any buffs, the number disappears.
To answer your other two questions:
- Yes, you can influence the number by remaining in range and in line-of-sight of your teammates.
- Yes, a higher number is better. :)