Just battery Snow and he will work.
Just a short clip showing the consistency of Snow's HP damage at different HP thresholds. Don't want to show the entire thing because it is way too long waiting for the follow-ups and bosses to react one by one.
Split damage LD preemptive attack on 3 targets with little overflow, BRV damage up and HP damage up, very consistent till the end. (around 180k on each target). Probably put Paine to the right for more HP damage up with 3 targets next time, probably works better than extra 20% overflow and Brv gain.
His S1/S2 would still cap despite doing 1-2k Brv damage with only base HA. (still around cap at 310K with S2 while boss at 2x%)
His EX and the actual LD does not benefit much from the Brv gain, but still does decent damage.
Highly recommend at least getting his base HA. The innate 60% Brv Gain helps him tremendously without heavily requiring Brv damage to output HP damage, just battery him before his turn and he will do work lol.
With more HP damage up and overflow, his LD off-turn attack will have no problem hitting all 3 targets with more than 200K or more.