Eradication Slime

The Eradication Slime is a boss slime summoned in Wave 5 of the Slimepocalypse event or summoned using a Radiated Slime Crown after 3 bosses are defeated. The boss itself is very simple to take down, but it takes a lot of time, as well as it having a lot of phases.

Phase 1
The first phase acts like King Slime, however without the spawns. The ground shakes whenever the slime lands. It will spawn Radiation Slimes instead of normal Blue Slimes. Building an arena for this is highly recommended, as the Eradication Slime can't teleport to you if you get to far, as well as not being able to jump too high. Go on a high platform and shoot it from afar.

Phase 2 and 3
The second and third phases both have radiated missiles raining down at high velocities, as well as larger purple bolts in Phase 3. For this phase, stay at a diagonal from the slime, as the missiles and bolts have a higher chance of landing where the Eradication Slime is. The spawn rates for the slimes are drastically increased in both phases, as well, but as long as you can stay up on a platform, the first half of the fight will be easy.

Phase 4
The fourth phase gets harder, as the slime can teleport, jump higher, and jump longer. In this phase on, the speed of the slime adapts to your movement speed. It will always move 85% of your top movement speed. If the player is on asphalt, but does not use its speed advantage, the slime will move faster than the player. For this phase, constantly run away from the slime. You will want to build more than one high platform for this phase. Run away from the slime while shooting it, while waiting for it to teleport. Since it always teleports in front of you, when it teleports, grapple up to the next highest platform and continue.

Phase 5
The fifth phase is identical to the fourth, but with faster fire speed. It loses a lot of defense, so try to keep close to the slime and DPS like a madman. The slime will get a lot of defense in the next phase, so try to lower it using a defense-lowering weapon, maybe from another mod.

Phase 6
The sixth phase is the second-to-last one where it loses all of its powers. This phase is a 'break phase', to prepare you for the last phase, which is the hardest one. Try to stay at a diagonal when aiming at it, as it will help you on Phase 7.

Phase 7
The hardest phase. The Eradication Slime becomes immune for 30 seconds, and it gains the power to fly. It flies in a circular pattern around the player, shooting purple bolts and radiated missiles. It can also create any type of ordinary slime every 15 ticks. For this, try to get away from the slime so the circle becomes larger, and you have more time to react to all the projectiles. Once the thirty seconds are over, the slime starts to go crazy and gets a large increase in fire rate. Over a course of 20 seconds, the circle slowly gets smaller, until it reaches 5 by 5 blocks. In this sub-phase, you should try to use a homing attack, because of the increased turn rate in the second half.

Aftermath
Defeating this boss for the first time allows Radellic Ore to spawn underground.