Outside of Kirri themselves, its a great help to the deck to make the plant tokens Yuma makes even more threatening and helps gets your lands back to make even more tokens
Arcane Denial never made much of an impact on constructed formats of the time as it was around at the same time as many of the other strongest counterspells and being so old it has never been able to feature in the more current extended formats
Haywire Mite was a game-changer for green decks with Urzas Saga, giving them a powerful tactic against other Saga decks if your Saga ends first, you can find Haywire Mite and remove theirs before it can get most of its value
Prior to 2003, the set symbol and number were sometimes placed on the bottom left of the card, and in the earliest sets, such as Base Set and Jungle, no set symbols were used at all
Basically, if you can't win with free mana, cards and 4/4 fliers then something is seriously up
Then, K type, this Character gains +3 cost