Freezing Mana

[Arrr]

Hot to freeze mana, like when you use a summoning spell, as long as the summon is alive, the mana used to cast the spell remains frozen
Example: hero has max10 mana, uses a summoning spell which costs 3mana, and as long as the summon is alive, his max mana will be 3

 

[axleion]

his max mana will not be 7?

anyway, if you intend to change the maximum mana, you can use BonusMod or create your own bonus ability.
for the spell trigger itself, you add the negative bonus to the caster, then set a timer with low interval, checking if the summon is still alive or not, then retrieve the negative bonus if the summon is dead.