So, Issue Number One: That is a
Level Ten Lich, and the party's highest-level character is level 5 (Belle) followed by two level 4 characters (Ryza and Octavio). Importantly:
Combat Mechanics said:
All player characters, and certain powerful bosses will have skills that allows them to alter dice, re-roll dice, or gain automatic successes in certain circumstances. They will typically have two: a personal skill that is unique to the character, and a class skill based on their class.
That is almost certainly the case here. We can also expect Tier 2 Magic, if not Tier 3. And our dear friend the lichekete is going to be rolling
eleven dice that succeed on rolls of 7+.
Several possibilities come to mind:
1) The party can't win this fight.
2) This is a puzzle boss.
3) This boss is significantly weaker than normal for its level.
I doubt 1 is the case;
@SoaringHawk218 specifically said that he wasn't recommending running, only reminding everyone of the option. Possibility 3 is probable, and the whole teleport + shield thing along with recovering HP stinks of some kind of obtuse mechanic that involves switches, levers, or having people stand in certain spots.
So, we know what the lichekete wants: dragonstones. It wants to feed. We also know that the doors
were closed when the party got here, and the lichekete was 'starving.' Which suggests a ... possibly desperate gamble to my mind, one that would greatly benefit from save-scumming in case I'm very off the mark.
If the lichekete is desperate enough, it might be willing to be drawn
out of the crypt by someone going, 'Hey, here's a dragonstone, come and get it, neener-neener!' And if it does follow that person out, then someone big and strong might be able to reseal the crypt - which might be enough to disable its teleportation.
Problem 1: The party has at most two dragonstones, one of which is damaged, and the whole one would be needed to enable the resealing of the crypt. And the damaged one is Ryza's father's.
Problem 2: Resealing the crypt
might not work.
Problem 3: If resealing the crypt
does work, the lichekete will probably get
more desperate, in which case whoever is holding Ryza's Dad is probably priority #1 or #2 (depending on whether a full-on Dragon-form manakete is considered more of a priority). (Might change depending on whether or not Ryza can do a quick-shift fast enough to get
past the lichekete to ram the doors shut before it realizes what happens.)
Problem 4: Communicating the plan to the party quickly, and convincing them.
Problem 5: Surrounding the lichekete and beating it down.
I'm bringing this up because the vicious monster within me says that there is
no way this lichekete's Shield+Drain move is a one-off, and the only other way I can think of to disable it would be to go around and
break the dragonstones in the shrines. Which might be a form of mercy-killing, but ... would still rather not.