If you are an experienced player and the bosses in the game have become boring for you, try installing this mod. Thanks to him, with every death, the Ender Dragon and the Searler will become stronger, they will have more life and during the battle, small assistants will appear next to them, preventing you from attacking the main target.
Progressive Bosses Mod for Minecraft 1.15.1/1.15
In general, bosses will now be much more powerful. Prepare your weapons and enchant your armor. You have a really hard fight.
Download Link: ProgressiveBosses_1.15.1_2.1.4