I did several events and i do raids.
Whenever i get an enemy that is 3400 i’m likely to beat him.
Whenever i do an event and the last level is 3400 i’m very likely to loose and must use gems to get another turn.
Are there different kinds of HP?
If this already has been asked earlier please be my guest and merge this to that topic.
The 3400 figure is a little different in these two contexts. In raids/wars, it is the sum of the heroes’ and troops’ power. In events, it’s the devs estimate of how powerful a team you will need to beat the level.
It sounds to me like you need to hone your strategy of completing quests/challenge events. Spend some time reading about how to do well in challenge events; these lessons apply directly to quests. In short, get all your specials ready to fire going into the last level, bring powerful battle items to smash the bosses.
Powerful materials as in dragon attack, time stop and the globe thing? (now leveling forges to 20 
)
Thanks for answering. You’re a wonderful help. I will look up some topics about this. Are they in the player guides parts or in the game and tactics parts? 
Try using a healer heavy team like 2-3 healers. Then after every Mob wave spend time charging up your healers and getting your team to full health before killing the last mob monster. If you go healer heavy you might want to bring direct damage items to clean up bosses fast such as Axes, Bombs, Dragon Attacks and Arrows.
And remember that your healers will NOT heal characters afflicted with the little red lightning bolt. If possible, hold off casting your healers until all those have worn off.