Found this online regarding grappling and eldritch blast...
Our warlock is grappled by a black pudding. There is a second black pudding standing in an adjacent square, currently not involved in the grapple. If the warlock activates his Eldritch Blast (S...
rpg.stackexchange.com
Weapon and Armor Proficiency: Warlocks are proficient with all simple weapons. They are proficient with light armor but not with shields.
Because the somatic components required for warlock invocations are relatively simple, a warlock can use any of his invocations while wearing light armor without incurring the normal arcane spell failure chance. However, like arcane spellcasters, a warlock wearing medium or heavy armor or using a shield incurs a chance of arcane spell failure
(all invocations, including eldritch blast, have a somatic component). A multiclass warlock still incurs the normal arcane spell failure chance for arcane spells received from levels in other classes.
…But it might be better for everyone to simplify things
This is, obviously, enormously complicated… and not a whole lot of fun. (Seriously, only the most paranoid or feat-rich warlock takes the feat Sudden Still of all things!) A DM that allows the warlock to just go ahead and blaze away with his blast while the warlock's grappled yet only provoke attacks of opportunity for activating the spell-like ability and making the ranged attack does the warlock's player—and, perhaps, all the players, including himself—a tremendous favor.
This part of the advice seems to be reasonable. So, Akos can activate the healing blast, but unless he does so defensively, he'll provoke an AoO from the Loyalist Akos hit with his own AoO. I believe the enchanter will still be cowering until after Akos turn is done, so she can't get an AoO vs. him. The other bad guys are close enough.
The standard Concentration DC for casting a spell (or using a spell-like ability) while grappling is 20.
(It seems weird that it is isn't 20 + spell level. If it was 20 + spell level, the DC would be 22 for Akos.)
EDIT: Hmm, might need to make two Concentration checks. One for grappling and one for using the eldritch blast defensively. That would be DC 20 and DC 17.
Also, the Rules Compendium says that retrieving a somatic component while grappling is a full-round action (and doesn't provoke an AoO).
