This [Chroma] is meant for killing Thumpers solo

Needs: Emmisive color set to either cold (white) (preferred) or toxic (green), Temporal Blast fully unlocked in Zenurik focus school and weapons set for radiation+cold (for which Thumpers are weak to) without +dmg mods ([Serration] and [Hornet Strike]) ([Rubico Prime] being my preference). Vigilante modset on sentinel weapons for extra crit % a bonus

Usage: activate level 5 bounty on plains in daytime, seek out [Thumper]. activate 3 and let him get your buffs up (preferred here would be to let it proc [Growing Power] and then activate 3), then start using your 2 and use void blast to slow him down and kill him with weapons by shooting the green glows on legs.

An alternative toxic build is up to the player, toxic gives firerate buff while cold buffs dmg more (since both rad and cold get buffed separately).