RESONANCE is a system that improves the ability of all the same servants just by having multiple identical servants. There is no need to spend and enhance like an existing game. If you don’t need it, you can sell it one by one.
Since contract servants have different abilities even in the same servant, it is also a strategy to have multiple possessions and use them according to the situation.

Servants will increase HP and POW each time they resonate. In the graph below, you can compare rarity and strength according to RES. The numerical value is the magnification when NOMAL RES1 is 100.

There is no status difference in the same rarity zone between Limited, Token, and Common Servants.

Limited servants have the advantage of definitely having plate skills, but there are also individuals who possess plate skills in tokens and common servants.

 

Considering the difficulty of collection for each rarity, the zone with a magnification of 140 to 180 in the graph below will be the main battlefield.

・ NOMAL → RES4 (140)～10 (152)
・ RARE → RES3 (140)～10 (172)
・ EPIC → RES1 (140)～4 (180)
・ LEGENDARY → RES1 (160) ～ 3 (180)
・ MYTHIC → RES1 (180)

The difficulty of training and acquisition increases as the rarity increases.