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
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.