They can come from the card you flip or cheat (Only the card you use, not every card), they can be built into the attack or action (like Francisco's Dueling Sword Ml 7 for example) and you can use soulstones to add additional suits. There's also some abilities that add suits like Somer Teeth Jones's Do It Like This tactical action.
So let's say Francisco attacks with his sword, spends a soulstone to add a ram and flips a ram card. He now has 3 rams in his final duel total.