Ok so after morogrim is dead i say we go for leotheras. t5 hands, and its about the same trash clearence as moro. We have a geared lock tank, and i feel we are upto doing this.
heres the general tactics, it reads as a hard fight but seems simple enough:

Abilities:

Leotheras alternates between Humanoid Form (~45 sec) and Demon Form (~60 sec) through most of the fight. He wipes threat upon transition between forms
At 15% health, the two forms split apart and must be handled together
Leotheras enrages after 10 minutes of combat, wiping the raid very quickly.
Humanoid Form Abilities
Melee: 2500-3000 on plate

Whirlwind:

12 sec duration
Leotheras spins around the room (similar to Sartura in Ahn'Qiraj)
~3000 damage instant (mitigated by armor) plus a 15s bleed for 2500 per 3s tick (no mitigation)
15 sec cooldown
Randomly switches targets during, and resets threat at the end
Demon Form Abilities
Chaos Blast : Leotheras' only attack in this phase, centered on his current target.

2 sec cast
150 fire damage AoE
Applies a 45 sec debuff which increases fire damage taken by 1675 and can stack up to 20 times
Inner Demon
About 25 sec into the Demon Form phase, Leotheras summons Inner Demons for up to five raid members (never for the person with aggro). The inner demons can only be attacked by the person to which they belong. If Leotheras returns to humanoid form while an Inner Demon is still alive, that person becomes Mind Controlled for 10 minutes (non-removable). Pet classes must make sure their pet does not get the killing blow, the Mind Control is only prevented if the player deals the death blow.

Inner Demon capabilities:

~11,000 health
melee damage: ~1000
spell damage: Shadow Bolt for ~3500 (reflectable)
take increased damage (+65%) from arcane, nature, and holy spells
take slightly reduced damage (-20%) from shadow and fire spells
vulnerable to most forms of CC like daze, stun, disorient, fear and even banish (not recommended)

Inner Demon sounds rough for the healers.

I think I can handle Demon Form. Just please give me a bit of time to get agro - I've only got one taunt ability; and with flame resistance gear on I'm not hit-capped, so it will have about a 5% chance to miss.

HURRAY, WHOHOO, CHEERS, HURRAY, WHOHOO, HURRAY
......

sorry.. i let myself go there.
i just hate long fights.
the shorter, the better.

EQ.

wow inner demon sucks for me.
Exorcism = 2k damage
consecration tick for 200.
Avengers shield 800 damage.
judgements 900.

thats gunna be a tight one.

Holy paladins:

Exorcism 2.4k
HolyShock 2.6k
Consecration 250/tick
JoR 1k
Damn healers having extra dps over me.

Leotheras for sure will be next , and this is going to be huge repear bills and sleepless nights of wiping .

he is some tutorial videos http://youtube.com/watch?v=FlOaGtzNq-Q
and wowwiki link http://www.wowwiki.com/Leotheras_the_Blind