Whenever Omo enters or attacks, put an everything counter on each of up to one target land and up to one target creature.
Each land with an everything counter on it is every land type in addition to its other types.
Each nonland creature with an everything counter on it is every creature type.
Omo's second ability grants every land type to lands with everything counters on them, not just basic land types. The full list of land types can be found in the Comprehensive Rules of Magic.