how to increase skill

[R25104871]

i have higt level now 38 but from the began i dont know about logo+ on skil button so i dont care, but but now i confused how to increase level of skill my slasher only level 2 ultimate slaser lever 1 very low power althougth at the academy i have increase hero PATK now level 32 but when batle at the same level with same sward my power is low

[kattuktk]

for every 2 level ups, u get to spend a skill point, just use that skill point to level up the skills which u want to level up(can also use it so unlock new skills)