Extreme Alchemy

Increases the potion level limit for some potions and adds a few new recipes. 

New potions:

• Haste (potion of speed 1 + nautilus shell)
• Mining Fatigue (potion of slowness 1 + prismarine shard)
• Health Boost (potion of instant health 1 + honey bottle)
• Wither (potion of poison 1 + wither rose)
• Resistance (awkward potion + scute)

New potions also have a level 1 long version

Upgradable to level 5:

• Strength
• Weakness
• Poison
• Regeneration
• All new potions

Potion level 3, 4 and 5 are made with Glow Berries, Glow Ink Sack and Lapis Lazuli respectively. Each additional level of potion reduces the duration by a small amount.

Haste

Mining Fatigue

Health Boost

Wither

Resistance

Level 3

Level 4

Level 5

Note:

This mod is NOT balanced for pure vanilla minecraft, especially the resistance 5 potion. This mod is mostly made for a specific modpack and is balanced around that. 

Once I get myself to learn how to make a config and add one, it will be rebalanceable however you like, until then you can use mods like CraftTweaker to disable or change recipes for potions.

Once I make a config I intend to make every vanilla and new potion upgradable up to level 10, but with level 6-10 disabled (4-10 for resistance) by default, as well as an extended (2x duration) variant of each level.
If possible I will give control over the max level of each potion, the upgrade materials for each level above 2, and whether potions above level 1 should have extended versions.

Before anyone asks:

• I have no intention of porting to anything other than Forge
• I will not be updating to newer versions, nor backport to older versions
• Feel free to use this in anything, I don't care about credits
• Copy and edit this all you want
• I am unlikely to update beyond what is stated (some more effects upgradeable, max level 10, config for customization and possibly extended potions for every strength)