I'm kinda worried my guardian monster ain't strong enough considering its cost. You guys got any thoughts on whether that's true or not?

[hider=Guardian]
Name: Silencer
Level: 8
Attribute: LIGHT
Type: Spellcaster / Effect / Guardian
Effect: Can only be Guardian Summoned when your Life Points are 3000 or lower. Banish two Level 7 or higher "Silent" monsters with different names from your Graveyard to Guardian Summon this card. When this card is Guardian Summoned, cards and effects cannot be activated. As long as this card remains face-up on the field, your opponent cannot activate Spell Cards. The effects of all Spell Cards your opponent controls are also negated. If this card destroys an opponent's monster by battle, gain 300 ATK.
ATK/DEF: 3000/2000
[/hider]