because 7+2 has the maximum set bonus, 20% in total regardless of colour. meaning 10% red 10% crit or 20% mag or 20% def.Thanks, I will slowly build 5* one slot attack rune as I am currently using the second option. I seem to remember a discussion here about the second option as a slightly better one, I guess that is obsolete.The first option is better in term of stat gain. This is what you'd want to go to for end game.Another question which is better for attack rune
- 7 one slot rune and a 2 slot rune
- 4 2 slot runes
The second option is better in term of cost. This is what you'd want to go for if you're lacking resource. But you'll eventually have to switch to first option.
If you use four 2slot = maxed of 10%, the 10% is not much, but compare to end game where you would not want to keep a 10% rune set if you could already get a 20% set.