Your search for "The Reliable Guardian SRL-044" revealed the following:
The Reliable Guardian - SRL-044 - Common - Unlimited from Spell Ruler Unlimited, available at 401 Games Canada. Rarity: Common Card Text:Increase 1 face-up monster's DEF by 700 points until the end of this turn.
The Reliable Guardian - MRL-044 - Common - Unlimited from Magic Ruler Unlimited, available at 401 Games Canada. Rarity: Common Card Text:Increase 1 monster's DEF by 700 points during the turn this card is activated.