Wada and the other guard troops were not present at the time of Cold's death and Frieza's first death, and apparently were unaware of Frieza's revival and second death. As such he was unaware that the Z Fighters even existed, only being aware that Frieza and Cold had been killed upon invading Earth, after having the planet scouted and discovering the "strongest man" Mr. Satan he and the other guard troops chose not to invade until he was dead, as they knew they could not deal with the one who defeated Frieza.
After Mr. Satan's death, the guard troops finally ordered the invasion of Earth in Age 820, leading to a full planet wide conflict and many deaths, and finally culminating in a battle between the aged Z Fighters and the Galactic Frieza Army, Wada survived the conflict and went on to lead the Frieza's army remnants on Earth years later.
Wada planned to revive his master Frieza once more. When the Time Patrol attacked his facility Wada himself came out to confront them, however the Time Patrol managed to defeat him in battle.
Wada relies on his brute strength when fighting, using his large size (twice that of a human) to deliver powerful blows.