@protoaddict 6/4 is the ultimate power/toughness anyway so you still come out ahead.
No, that's a relevant point though. I think that infect in Vintage has been a very fast goldfish that's very easy to poke holes in, and this card makes the goldfish faster and/or easier to assemble but no less hole-pokeable.
Whenever you change P/T of a creature it always retains the buffs. You just change the base power and toughness.
I'll defer to what I assume is your superior rules knowledge... I assumed this was a complicated layering thing but I probably was overthinking it.
@craw_advantage yeah, this is pretty much not an issue as a rule. It's been like this for quite a while, it's just that in Vintage we don't get those scenarios that much so most Vintage players don't need to know it.
I guess the only time this came up recently was with Chief of the Foundry - your 0/0 Ballista with 2 counters on it became a 1/1 Ballista with 2 counters on it.
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.
@thewhitedragon69 I assume you're talking about the blazing infect deck, which is fun.
This card might make an infect deck with similar explosiveness but much higher consistency. Plus I got rid of most of the edh creatures the deck was force to run to support blazing shoal.