It's my understanding that Ion Deluge only works for the remainder of the current turn, therefore it only works in Double and Triple Battles. Doubles Battles were not introduced until Generation III and Triple Battles until Generation V so even if Ion Deluge was present in Generation II it would not work. However if Explosion still lowered the targets Defense by half in Generation VI then it would probably work and have a Base Power of 1000 (w/o STAB), but because you have to have a team mate set up Ion Deluge after you use Charge (the same turn you use Explosion), you would hit your own Pokémon with Explosion as well.