Supressor is able to supress any flame. Alros has to be careful when confronting him, because any spell of fire, even the firestorms and the firewalls, are useless against it. The Fire Surge of the Fairies of Fire is the only fire spell that can make some damage to this evil creature, but it is only if the player got the fairy of fire so Alros has the Fairy Wings of Fire that lets him to do that attack.
Otherwise, if Alros was enchanted by Menisne and he has a deer-head, he is able to release any Earth Spell he wants to. The Spell of the Nymph would be useful to make the grapevines to attack the Supressor. The Fecund Flowers spell will do major damage.
If Alros is not enchanted by Menisne, he will need a special item: The Thyrsus of Bacchus, to turn his fire attacks into earth attacks (the flames becomes poisonous snakes that destroy the enemy).
The thrysus of Bacchus is found in the center of the vineyard, and without this item nor any other plus it will be by far more difficult to defeat the supressor.