Diablos has two of the most important abilities in the game: Mug and Enc-None. The damage from his attack gets exponentially more effective as Diablos levels up, but make sure you learn Mug and Enc-None as soon as possible!
Attack Name: Dark Messenger
Attack Effect: Demi/Gravity based attack
How to Obtain Diablos
Headmaster Cid will give you a 
Magical Lamp at the entrance to Balamb Garden just before you leave for the Forest Owls Mission in Timber. Examine the Magical Lamp to begin the battle against Diablos, and once you defeat him, he will join you as a Guardian Force.
List of Abilities
| Ability | AP | Effect |
|---|---|---|
 HP-J |
50 | Junctions Magic to HP. |
| Mag-J |
Junctions Magic to Magic. | |
| Hit-J |
120 | Junctions Magic to Hit. |
| Abilityx3 |
Allows 3 support Abilities on character. | |
 Magic |
Use Magic command in battle. | |
| GF |
Use GF command in battle. | |
| Draw |
Use Draw command in battle | |
| Item |
Use Item command in battle. | |
| Darkside |
100 | Use Darkside command in battle. |
 HP+20% |
60 | Raises HP by 20%. |
| HP+40% |
120 | Raises HP by 40%. |
| HP+80% |
240 | Raises HP by 80%. |
| Mag+20% |
60 | Raises Magic by 20%. |
| Mag+40% |
120 | Raises Magic by 40%. |
| Mug |
200 | Attack and steal Items at the same time. |
 Enc-Half |
30 | 50% less random encounters. |
| Enc-None |
100 | No random encounters. |
 GFHP+10% |
40 | Raises GF HP by 10%. |
| GFHP+20% |
70 | Raises GF HP by 20%. |
| GFHP+30% |
140 | Raises GF HP by 30%. |
 Time Mag-RF |
30 | Refines Time Magic from Items. |
| ST Mag-RF |
30 | Refines Status Ailment Magic from Items |
- Ability is already learned when Diablos joins you as a Guardian Force.