Farming legendary duelists is extremely important in Yu-Gi-Oh! Duel Links as it is the only way to get some of the most powerful cards in the game. However, farming certain duelists in the most effective way possible often requires specific cards in order to build a deck that will reward the most points. Almost all of these decks use the extraordinarily powerful Union Attack card, which adds up the attack of all face-up monsters on your side of the field and gives it to whichever monster you choose. This allows cards like Gravekeeper’s Vassal to unleash powerful 10,000+ damage strikes.
Unfortunately, acquiring Union Attack is not an easy feat. The card itself is a drop from a legendary duelist and only one that appears during specific timed events. The duelist that drops the card is Yugi Moto (not to be confused with Yami Yugi). It is a Super Rare card so the drop rate for it is fairly low and when paired with the multitude of other cards that Yugi Moto can drop, well, the likelihood of getting the card falls pretty low. There are some strong deck combos that will increase the change of it dropping by rewarding higher points, such as the Unhappy Girl deck, many of which can be found here. The event comes and goes at regular intervals and is normally active for only a week. During the event, Yugi Moto will appear around every 1-2 hours or so.