I have a question concerning Saga of Grungni Action, to be exact I'am not sure how to interpret the line:

"While this card is recharging, allies with whom you are engaged may not be targeted by any hostile effect….

What is meant exactly by the "hostile effects"?

Thank you in advance for the answer.

All attacks I guess, it's basically a "tank" action, that allows you to draw all the attacks to you as the enemies cannot attack your friends.

Hostile effects means attacks, certainly. Any other hostile actions and effects, that may or may not be interpreted strictly as attacks, would also fall under this. Social influences, non-damaging spells, etc.

Keep in mind that it only affects/protects allies that are in the same engagement as the user of the saga. Any allies that are not in the same engagement are fair game.