This is an event that is pretty much like our current Bahamut one but is currently happening over at the Japan servers. This time round, the special 5* is the same shape as all the non-special ones so no Giant-resetting trick can be used. I can't wait for this to arrive at our English servers.
Once again, I'm compiling ahead using the Guardian Cross (GC) Jp Wiki.
5*
Lightning
Gilgamesh
Shape: Giant
Skills:
Level 1: Last Stand (revive with 1HP, I think?)
Level 15: Call Lightning (lightning+3)
Level 30: Greater Cunning (wisdom+20%)
Level 40: Slow (agility-20%)
Level 50: Chain Lightning (lightning+4)
Comments: High stats overall, only agility is the weakest. However, it has high HP and wisdom and make for a very good tank Go for Skill 1, 3 and 5. (Skill 3,4 and 5 looks good too but that "Last Stand " skill is too good according to the JP Wiki recommendations. If it is a revive like ability, it is definitely worth it)
Update 10/11/2012: Last Stand is a revival-like ability except that you return with 1 HP and 1 MP. It makes fast and powerful type important to get the additional and strong hit.
4*
Machine
Dwarf Gear
Shape: Giant
Skills:
Level 1: Hard Slash (physical+3)
Level 15: Might (attack+10%)
Level 30: Greater Haste (agility+20%)
Level 40: Greater Cunning (wisdom+20%)
Level 50: Greater Might (attack+20%)
Comments: I like the art on this one. The most interesting part about this Guardian is that it gets 4 good buffs and you get to make your own choices. This makes Intelligent, Powerful, Fast types all good. However, Intelligent types require a elemental +3 attack stone. It's hard to recommend the skill path to take, you can either go all-out attack or offensive-physical or offensive-elemental.
Earth
Bugbear (Hope I got the name right!)
Shape: Giant
Skills:
Level 1: Ice Spike (earth+2)
Level 15: Heavy Blow (physical+2)
Level 30: Defence Down (defence-20%)
Level 40: Double Impact (physical+3)
Level 50: Rock Bite (earth+3)
Comments: Compared to the other Giants, this one doesn't look as strong. I will say the overall stats are average. The last 3 skills are the best.
Update 10/11/2012: Powerful type will be good to complement the defence debuff.
Death
Bune
Shape: Giant
Skills:
Level 1: Greater Protect (defence+20%)
Level 15: Death Touch (death+2)
Level 30: Greater Cunning (wisdom+20%)
Level 40: Dark Pain (darkness+2)
Level 50: Revive (revival)
Comments: This Guardian comes with the new Death elemental attacks. I think it will be first introduced in the 4th Hunting Ground Desert zone. Those attacks have a probability to 1-hit kill anything! This guardian can easily become the best 4* because it just needs to be fast/"tanky"/revive and you need to have luck and it may easily take down more than 2 maxed level guardians which is the most we hope for in the high-level coliseum battles. Once the death skills/stones arrive in our game, all hell will break loose! Did I mention that it comes with revive? Skills 2,3 and 5. (Skill 3 isn't even needed. You just want to cast death+2 as many times as possible in battle)
Darkness
Balor
Shape: Giant
Skills:
Level 1: Dark Pain (darkness+2)
Level 15: Slow (agility-20%)
Level 30: Defence Down (defence-20%)
Level 40: Cunning (Wisdom+10%)
Level 50: Dark Psalm (darkness+3)
Comments: This guardian should be an elemental attacker. I think the attack stats might be too low to be potent even with the Defence Down debuff. Chaotic types might want to go the physical route with a physical+3 stoning as wisdom stat is reduced. Following JP Wiki's recommendations, use Skill 2, 4 and 5.
iTunes App Store link: Guardian Cross - SQUARE ENIX