This is well describe by rule 613.3, the order is
Effects from characteristic-defining abilities that define power and/or toughness
Effects that set power and/or toughness to a specific number or value are applied.
Effects that refer to the base power and/or toughness of a creature apply in this layer.
"Avultar" apply here.
Effects that modify power and/or toughness (but don’t set power and/or toughness
to a specific number or value) are applied.
Power and/or toughness changes from counters are applied.
Effects that switch a creature’s power and toughness are applied.
Because @ChubbyRain is waiting it
Plague Engineer 2B
Creature - Carrier
As Plague Engineer enters the battlefield, choose a creature type.
Creatures of the chosen type your opponents control get -1/-1.
He answers the token generator like Mentor and Young pyro.
He weakens tribal deck like Human, Eldrazi etc
He can be a 1 for 1 answer to specific 1 toughtness creature like revoker.
He can attack.
He can chump block.
So which deck want him, Survival, UBx control ?
The number of set (with at least one new card) by year:
The number of new printing by year:
The year 2019 is ongoing so the number are incomplete.
There seem to have an increase in the number of new printing in the last few years.