Additionally there are several 'classes' or tiers of elemental that are stronger then the previous.Elemental's can be summoned using the summon elemental spell. Each variant has traits unique to their element. Elemental's are powerful pawns added to the game.They come in several elemental variants.
The tree is generated when RimWorld is loading, you won't get interrupted by the tab. This is a fork of ResearchTree by Fluffy. There's also Coal Liquefaction, which came a few years after 0.13. The output is also improved by infinite-productivity research, increasing their output the longer your megabase runs. Today, this minimum has been grossly buffed, greatly reducing the number of depleted pumpjacks you need in endgame.