Sage Mode can be learned by first crafting a Sealed Sage Scroll that can only be opened by one of the three Sannin. After completing the tasks presented, Sage Mode can be activated by pressing the Sage Mode key. It is only possible to have one Sage Mode Type at a time.
The current sage mode types in the mod are;
Slug (Tsunade - Jungle Biome)
Toad (Jiraiya - Mesa Biome)
2 Variants of Toad
1.The normal Toad sage eyes ( Naruto)
2. Naruto sage mode eyes (with cloak and summoning scroll)
Snake (Orochimaru - Swampland Biome)
Each vary in designs around the eye but generally have the same effect of a major speed boost meaning type matters very little.