Affinity Boost
From Shin Megami Tensei IMAGINE Wiki
Affinity Boost is a type of Damage Boost:
They are the only boost that is naturally capped at 100%. This cap can be increased for most affinities in the Cave of Life, or through Demon Force.
In most cases, it will look something like this: (Affinity)高揚+(Amount%)
What falls under this:
斬撃: Slash 突撃: Charge 打撃: Blunt
射撃: Handgun 貫通: Penetrate 散弾: Spread
火炎: Fire 氷結: Ice 電撃: Electric 衝撃: Force
破魔: Expel 呪殺: Death
魔力: Mystic/Magic 神経: Nerve 精神: Mind
回復: Curative 万能: Almighty
Despite the description, the Cerberus/Orthrus set bonus does not fall under this damage type. Instead it falls under Action Boost.