You can Special Summon a level 5 or higher "Ice Barrier" monster from your Graveyard if you Normal Summon it. The Level limitation only applies if you Special Summoned it by its own effect.
Activate the second effect of "Tidal, Dragon Ruler of Waterfalls" to send a strong or strategic "Ice Barrier" monster from the Deck to the Graveyard, then tribute this card to Special Summon the sent monster.
Alternatively, while "Defender" and "Secret Guards" are both in your Graveyard, revive both in Defense Position to create a lock.
Use this card to help the activation of several "Ice Barrier" effects, since they normally need another Ice Barrier on the field. If you choose to stall, you could even Summon one of the Generals next turn.
If two "Priors" are in your hand and "General Grunard of the Ice Barrier" is in the Graveyard, you can Normal Summon one "Prior" to bring back "Grunard". Then, use "Grunard's" ability to Normal Summon the second "Prior", allowing you to get over the restrictions of "Prior" and provide you with a 2800-ATK monster.
If you have multiple copies of this card in the hand, and "Dewloren, Tiger King of the Ice Barrier" on the field, Special Summon them and Normal Summon another monster before using "Dewloren's" Effect to gain up too 2000 ATK (3 "Priors" and a Normal Summon)