ATK * (8 + (Remaining SP-1)/10)
Lv 5 means +1000 extra final dmg on this formula.
luna has an atk of 110, lich 60.
let's play with an easy 795 sp champ with 100 str with 109 total dex[221 atk from stats]
[(Total Attack) x ( 8 + SP/10 ) + 1000] x Carded Mods = lv5 asura formula[I think]
luna with 2 ak+1 element = 1.8 mod
[(221+110)*(8+(795-1)/10)+1000]*1.8 = [331*(8+79.4)+1000]*1.8 = [331*87.4+1000]*1.8 = 53872.92
lich +9 with 2 ak = 1.5 mod and a +300 sp increase
[(221+60)*(8+(1095-1)/10)+1000]*1.5 = [281*(8+109.4)+1000]*1.5 = [281*117.4+1000]*1.5 = 50984.1
Some random input check to give a better clearance of what I'm talking about:
Formula at 5 - ATK * (8 + Remaining SP/10) + 1000
2*(8+(2-1)/10)+1000 means 1 sp to cast, 1 sp used on an asura with 2 atk to check numbers. ends with 1016 dmg
Checking the same equal number for sp values -> 1*(8+(X-1)/10)+1000 = 1016 <=> x-1 = 80 <=> x=81
that 1 is the asura cost so 1 atk = 80 sp
lich gives 300, 300/80 = 3.75 atk increase
luna has 50 more atk then lich
3.75 < 50
luna wins
50-3.75 = 46.25 atk difference
46.25*80 = 3700 sp difference
Since +5 is the safe refine lv for luna and lich is +9 and if
this is correct, it should be just a difference of 28 atk so it's less 2240 sp in that 3700[no clue about how this things work to be honest lol, just playing with numbers and nothing more]
3700-2240 = 1460