If this card is Normal Summoned: Place 2 Spell Counters on it. Each time a Spell Card is activated, place 1 Spell Counter on this card when that Spell Card resolves. This card gains 300 ATK for each Spell Counter on it. Once per turn: You can remove 2 Spell Counters from this card; Discard 1 random card from your opponent's hand.
Citadel can be used to store some spell counters early, and it can use the spell counters as a substitute for your other monster(s) that need them. You can summon Dark Red Enchanter as a surprise to discard 2 cards from your opponents hand when you summon it.
Spell Power Grasp will give 2 spell counters when you use them, increasing Enchanter's attack by 600, and can get another copy of the spell card if you have more in your deck. It's recommended not to use enchanter's effect right away if you only have 2 spell counters, since it will leave him with low attack.
If you are using a field spell, you can use Murmur of the Forest to return it to your hand, allowing you to activate the spell again to get another spell counter. This will also return your opponent's field spell (if they are using any), lowering their monster's stats, and possibly making them use the field spell again. Since most monsters also have low defense stats, flipping them face down can make them easier to destroy, essentially giving you multiple advantages at once.
Legion lets you tribute summon into Dark Red Enchanter right away. You can then activate Enchanter's ability right away to randomly discard your opponent's card. Make sure you have some spell cards as protection to make sure you don't leave Enchanter with low attack.