I believe Karis meant Venom and Deadly Venom?
Poison and Deadly Poison are spells and Poison is also an activated ability (I also suggested a Deadly Poison [2] as an activated ability)
If Karis meant it to be an activated ability it would have an activation cost.
It does not.
Therefore it must be the Automatic Active ability Venom|Deadly Venom that people commonly misname.
T1: 5|7
T1.5: 5-1=4|+7-2=5
T2: 4+5=9|5+7=12
T2.5: 9-2=7|12-4=8
T3: 7+5=12|8+7=15
T3.5: 12-3=9|15-6=9
T4: 9+5=14|9+7=16
T4.5: 14-4=10|16-8=8
T5:10+5=15|8+7=15
T5.5:15-5=10|15-10=5
T6:10+5=15|5+7=12
T6.5:15-6=9|12-12=0
T7:9+5=14|0+7=7
T7.5:14-7=7|7-14=-7
T8:7+5=12|-7+7=0
T8.5:12-8=4|0-16=-16
T9:4+5=9|-16+7=-9
T9.5:9-9=0|-9-18=-27
...
As we can see if Karis meant the activated active ability Venom then this card is UP.
If Karis meant the activated active abilities Venom|Deadly Venom then accurate attack would be -1|-2 derived from Forest Scorpion and Deathstalker.