Dont rush yourself to change high grade, keep killing alien in I grade and join raid if there is team for raid to get more agra (more agra = more stamina = more hit).
Dont forget to train your Practice Point (PP). Buy sniper for train PP, with sniper, you have a greater chance of success in training PP. And also dont forget to join in tournament battle everyday, because you need captain rank (240 M dmg) to can change to E grade. click here for more explanation about military rank.
After you have atleast 120K PP, try to change grade to G grade. why? because in I grade you cant do solo raid, sometimes in I grade there are no players joining the raid team, but in G grade you can do solo raid, so if you have 120K PP you can kill raid alien G with 2 shoot, and more high grade raid, you get more blue and red agra.
My advice, before you change to G grade, it is better you buy H and G grade item first (full set of H and G grade cloth, H and G grade pistol, H and G grade sniper) to avoid the mistake.
Stay in G grade until you have 2.5 million XP and military rank captain. And buy full set of F, E, and D grade armor, F grade pistol LQ, full set of E grade cloth, E grade pistol, E grade sniper, and D grade pistol LQ.
more explanation about red text:
- full set of F, E, and D grade armor: without full set of armor, the DP that has been shared with you from another player will not work. This DP you need to kill aliens that drop E change grade items, D change grade items, and the Astral Drake Of Mizar Elevens that drop the Rebirth almanacs.
- F grade pistol LQ: why only pistol? and Low Quality (LQ)? because you dont need too much time in F grade, that why i write to have 2.5 million XP and have captain rank in G grade first. in F grade you just need to kill alien that drop E change grade item.
- full set of E grade cloth, E grade pistol, E grade sniper: why E grade must complete item? because you will need alot of time in E grade, you need to win tournament in top 3 (on the winner side) for 7 times to get 7 E change grade items, if you have some money, buy E grade launcher to can have more big damage in tournament battle.
- D grade pistol LQ: same for F grade, you dont need too much time in D grade, just make sure spend your stamina until 5 stamina left before you kill the Hyperbasher Of Castor and change grade to D. And then direct kill the Astral Drake Of Mizar Elevens in Moskva for 10 times.