Hey ppl, remember that toxic will sooner or later reduce all of its HP, even if the HP bar is full. So the battle will be over in 5 turns, unless Ho-oh can somehow heal the poison.
Turn 2: Ho-oh's HP is 15/16, Lugia at full health.
Ho-oh uses Toxic, Lugia uses Water Pulse.
Ho-oh loses 1/16 HP (Lugia's base attack isn't high, added to the Sunny Day). Lugia is badly poisoned, loses 1/16 HP. Ho-oh loses 2/16 HP because of poison.
Status: Both badly poisoned, Ho-oh 12/16 HP, Lugia 15/16 HP. Ho-oh's Toxic PP is 8/10. Lugia's Toxic PP is also 8/10. Sunny Day (Ho-oh) PP is 3/5. water Pulse is 18/20 PP.
Maybe Toxic shouldn't be included. It makes it a race against time. Next battle, no Toxic.