The D M

+2: roll a d20 if you get 1-10 you gain 1 life 11-19 target opponent losses 1 life 20 you gain 3 life target opponent losses 3 life
-3: roll a d20 if you get 1-10 target creature gets -1/-1 11- 19 target creature gets -2/-2 20 destroy target creature
-18: target opponent rolls a d20 if they roll 20 nothing happens if they roll 1-19 create a 100/100 Tiamat token with indestructible