Mage best combo

Looks like 3

 

how can you guys tell? I dont really get how so many skills in a combo will cost 1mp. How does it work? It's really confusing. Sorry noob here

 

Its actually 4mp
Impact-->storm(smite)-->javelin(save)-->arrows(smite)
1.)1st skill impact will consume 2mp.
2.)2nd skill storm is 4mp but it will become half cost because on impact so another 2mp consumed.
3.)3rd skill is javelin with save tag (save tag means that skill will cost no mp and its mp will turn into an mp bank which can be used to consume the cost of the following skills in the combo) so here 2mp javelins cost will be saved.
4,)4th skill is arrows with smite tag (smite tag increases dmg of the skill but if the smite tag is added the cost of the skill doubles thats arrows 1mp will become 2mp) so the 2mp cost will be canceled by the 2mp bank of javelin so both of them will cost no mp.
Total cost=2+2=4mp
There was a guide to combo tags but i cant find it anymore.

 

Impact - Storm (Smite) - Javelin (Save) - Arrow (Smite)
[MP : 4] [Storm : 150% , Arrow : 90%]
Impact costs 2MP .
Storm becomes 2MP because of impact's skill effect of reducing the next skill's mp cost after it to half.
Javelin will cost 0MP because of Save Tag and the 2MP original cost of javelin would be saved as a mana bank that could be use for the next skills after this one. Save tag will reduce it's dmg to 50% and the skills after save tag would get a reduction of 60% and subsequent skills after it would get 40% , 20% and 0% dmg reduction.
Arrow would become 0mp , originally it should be 2mp because of arrow's original mp cost of 1mp but due to it having smite tag on it despite being at the 'end' of combo , it would have a penalty of x2 of its original MP costs. But due to the 2mp mana bank that came from javelin's save tag , it would be used instead so it becomes 0mp. Regarding its damage , it becomes 90% because of 60% reduction due to the save tag used before this skill but it also has a + 50% dmg increase from having a smite tag so it's overall would lead to -60 + 50 = -10% , 100%(original dmg of arrow) -10% = 90% arrow dmg.

Overall this is a very poorly made combo.