I looked on all foruns and I didn't find anything that could explain my doubt, or I'm too dumb, or anybody wanted to ask (Hope that is the second one), but I looked on Proto-Tyrant and did not understand it's effect.
Could anyone explain it for me please?
If you explore and defeat him you attach him to your character, if you don't you get the normal damage. The effect is that every non-exploring character, so everyone except of you, get 40 damage when he is revealed and if they have 50 or more health. So if you play, for example, in a group of 3 (Player 1 = you, Player 2+3 your friends) and you explore and you reveal the Proto-Tyrant you ask your friends how high their health is. In our example player 2's health is 40 and player 3's health is 50 and yours is 60. Player 2 takes no damage (because he has less than 50 health), player 3 takes defiantly 40 damage and you only take damage if you couldn't defeat him, no matter how high your health is.