Hey all. I figured I would write a succinct guide on the first boss of Spiral Knights, The Jelly King. This is not meant to be exhaustive, or "THE BEST STRATEGY EVAR", but more a guide to folks who, like me a short time ago, have no clue what to expect going into their JK run (or have gone on one, and would like to know why they failed or how they could do better next time). Suggestions and constructive criticism are welcome!
WHERE:
Always available on at least one gate--the Jelly King is in Tier 2, on the 17th gate (the 15th and 16th gate are its palace, leading up to it)
WHEN:
As soon as you can access tier 2, it is a good idea to start doing JK (Jelly King) runs. It is significantly more challenging in 2*/3* gear than it is in 4*/5*, and soloing (unless you are quite skilled) is very challenging without the proper equipment (again, 4*/5* gear).
WHY?
The Jelly King runs drop a significant amount of heat and crowns alone, but also typically provide sparks (usually Primal) from boxes and JK himself drops 3-5 Jelly Tokens.
--->WHAT ARE TOKENS?
--->They're used to buy valuable materials, as well as some of the most popular weapons in the game (Sealed Sword and Antigua, which become very powerful when upgraded).
Furthermore, the spawns in Jelly Palace, as well as the puzzles, are preset and 100% predictable as a result. It's easy to form survival strategies. In general, once you get the hang of them, JK runs are the fastest clockworks-derived crown (and thus, crystal energy) source in the game until Vanaduke runs.
HOW TO PREPARE?
ARMOR:
Any armor/shield that gives you normal defense is good. If it gives elemental defense (as there are gun puppies/etc in the Palace), even better. But the JK itself (and its legions of jellies/slimes) deals normal damage, so it's pretty much a must-have if you don't want to spend the fight on the floor. Lichens and floorspikes deal piercing damage, but it's fairly easy to avoid.
WEAPON(S):
Guns are not useless on JK as many people say, but due to his legions of jellies surrounding him, they take considerably more skill to use than a sword. Bombs can be helpful, but take a while to charge (leaving you vulnerable to aforementioned Jellies).
The JK RESISTS piercing damage (flourishes, antigua line), take NORMAL damage from Normal, Elemental, and Shadow weapons. Shadow weapons deal critical damage to jellies and slimes OTHER than JK itself, so that's something to consider for the levels leading up to JK. People have also had success with the Cutter line (in particular, the Vile line because of its poison application).
Join a party (or start one) in the Second tier of the gate that features a Jelly Palace strata.
ONCE IN THE CLOCKWORKS:
Collect 3 of as many of the following as you can and save them for the JK fight:
Poison Vials
Fire Vials
Curse Vials
Shock Vials
Health Pills
Stun vials--see edit below
You want to hoard these because they make the fight substantially easier. Curse causes damage to JK when it attacks. Fire does damage over time. Poison prevents healing (which the JK does enough to make poisoning worthwhile) and decreases JK's attack, making it the most important of the vials.
Edit: Quoting Magnus:
"Stun slows [Jelly King] down, so it can't attack twice in between berserks and you can unload much more DPS on it than any feminine little damage from a fire vial, making stun the second most useful vial for the entire boss fight. You should know these things before writing up a guide on it. It's very misleading to new players and can severely hamper their progress." Love you too, buddy! I'm sure the rest of the guide was useless, right?
THE PULL:
One player should destroy the blocks directly in front of the Party Button on JK's level (17). Using a bomb is good, or hitting the blue block to wipe them. Ideally, one player will be ready to throw poison, fire, and whatever. The button depresses, and JK and its minions spawn.
Strafe left or right around the minions and throw your vial at JK. Enter in to attack. Depending on your weapon type, you can probably get 2 attacks in before you need to shield from the JK's attack. If jellies are swarming you, "pop" your shield briefly to knock them back. Use your shield liberally and don't be afraid to leave the JK to survive--but don't bother attacking the little jellies because it's a waste of time, JK will just spawn more. Don't stand where the blocks respawn, as they will damage you when they pop back up.
-->PROTIP: Standing on the block walls as they regenerate does damage to you--but less damage than any other source in the fight (and providing you with temporary invulnerability after being "struck") so you can actually use this to your advantage, if you're careful/strategic about it.
Eventually, JK will turn pink and begin a large, rapid spin which you need to avoid. After that, you'll have a chance to attack it again (then shield for a regular spin) then attack again, then it will do the large spin again. This repeats until the JK is defeated, OR heals enough to return to phase 1 (where it does not do the big spin). This is why you want to try and keep JK poisoned/burning/etc for the duration of the fight.
Assuming you defeat JK, you will be rewarded with 3-5 Jelly Tokens and access to the treasure room/elevator behind it!
A few errors, from what I read on wiki
Jelly deals piercing damages
Poison decreases attack strength
Curse cause damage when JK attack