Stronger Wither

The wither is currently too easy to "cheese", you just spawn it underground and easily kill it while it cant fly cause its stuck in the tiny room.  To prevent this, the wither should need an "open space" in order to spawn. The bedrock wither should come to java, and its damage should be significantly boosted, as right now with maxed gear you can tank several skulls from multiple withers at once even on hard difficulty, and when you start getting low you just eat and the regeneration is faster than the damage from the wither. In addition, it should also have some kind of strong melee attack to make it more of a challenge in the 2nd phase.