Before Terraria's 1.4 update, it was basically impossible to beat the game as a Summoner. Besides the lack of minions to use and the fact that most of the minions that did already exist were terrible, the Summoner Class also didn't really have weapons of their own. Instead, all Summoner players had to use weapons from other classes if they wanted to make progress.
Because of the Journey's End update, however, the Summoner Class became one of the best in the game. Along with new and better minions, Summoners finally had plenty of great weapons to choose from.
Queen Spider Staff
One of the few weapons Summoners had before the 1.4 update is the Queen Spider Staff, which summons a Queen Spider sentry and can only be made during hardmode. Unlike minions who move around and follow the player, sentries stay in one place unless they are re-summoned somewhere else, and they disappear after a couple of minutes. The Queen Spider sentry fires spider eggs at enemies, and these eggs cause damage if they hit an enemy.
While this is one of the old weapons, it still works well for several reasons. If an egg hits an enemy, the egg bursts and two baby spiders crawl onto the enemy, which will deal some more damage and also give enemies the "Acid Venom" debuff. With all of this, this sentry does a relatively good amount of damage. Since Summoner players are probably spending most of early hardmode getting Spider Fangs to make the Spider Staff for the Spider minions, they can easily get enough to make this as well, which is a good companion to the Spider Staff and will be perfect for early hardmode enemies.
Staff of the Frost Hydra
Another old Summoner weapon that still works well is the Staff of the Frost Hydra, which is a post-Plantera weapon that summons a Frost Hydra sentry. The Frost Hydra fires magic ice pellets at enemies, and this attack deals damage while also knocking enemies back.
Since sentries will continue to attack enemies for a couple of minutes even if the player leaves the area or dies, these types of weapons can be great for fighting multiple groups of enemies. The only issue is that sentries cannot move and will disappear if they are not re-summoned. Also, while the Frost Hydra is more powerful than the Spider Queen, this weapon is harder to get because it is in the Dungeon's Ice Chest.
Gelatinous Pillion
While it may be surprising, some mounts in Terraria are also Summoner weapons that deal Summoner damage. This means that besides using them to move around, Summoners can also use them to fight enemies. Out of all the mounts that can deal damage, however, the Winged Slime Mount is the best choice, which is summoned by the Gelatinous Pillion item.
When combined with Summoner buffs and items, this mount can do a relatively high level of damage to enemies by jumping on top of them. Although the mount has a slow forward movement, it can jump really high, fly for a while in the air, and land without giving the player fall damage. Also, since it is one of the drops of the optional boss Queen Slime, it is one of the best mounts for Summoners because one of the best minion staves, the Blade Staff, is a Queen Slime drop as well. Since players can even attack using their slime vehicles, Terraria should also be considered one of the most important indie games.
Snapthorn
After the Journey's End update, whips were introduced to finally give Summoners the ability to attack enemies themselves without using weapons from other classes. In pre-hardmode, the player can easily make the Snapthorn whip using 12 Stingers, three vines, and three Jungle Spores at an Iron or Lead Anvil. Like all whips, the Snapthorn directs minions to the enemies that were hit by it, and minions also deal more damage to enemies that are tagged.
Besides its base damage and tagging ability, the Snapthorn also gives the player the "Jungle's Fury" buff, which increases their attack speed by 20%. Also, it inflicts the "Poisoned" debuff on enemies, which works well against the Eye of Cthulhu. Despite how easy it is to make, this weapon remains a useful possibility for Summoners all the way until after Plantera.
Spinal Tap
Another pre-hardmode whip that remains relevant until post-Plantera is the Spinal Tap. Compared to other whips in the game, the Spinal Tap is the best against large groups of enemies because it has the least damage reduction per hit in a single swing, which means that each additional enemy hit by the whip during one swing will still receive a good amount of damage.
But, the Spinal Tap does not give the player any buffs or the enemies any debuffs. Also, it can only be made after beating Skeletron because the player will need to use 90 bones along with 55 cobwebs to make it.
Morning Star
After defeating Plantera, some mobs in the Hardmode Dungeon will drop a Morning Star whip, which is one of the two whips in the game that give minions the ability to deal critical hits. With its high base damage, extremely low damage reduction per hit, and high knockback, this whip is perfect for dealing with tough late-game enemies.
The main issue with this whip, however, is that it's much slower than other whips, which can be a problem in certain situations that require quick attacks. Because of this, the whip is better when used with other whips as well.
Dark Harvest
During hardmode and post-Plantera, the player can possibly encounter a Pumpkin Moon event. If the player defeats a Pumpking, which is the hardest enemy in this event, then there is a possibility that it will drop a Dark Harvest whip. This whip applies a "Dark Energy" aura to targets, and if a minion hits those targets, then the aura expands and damages other enemies around the targets. Dark Harvest also gives the player the "Harvest Time" buff, which increases attack speed.
The whip, however, doesn't apply summon tag damage to enemies like other whips. Players will also struggle to get this because it is an event-only whip that only has a possible chance of dropping from a difficult enemy.
Kaleidoscope
Besides Morning Star, the Kaleidoscope whip is the only other whip in the game that gives minions the ability to deal critical hits. Because it has an extremely high base damage, speed, and a long range, it can easily be considered one of the best in the game. When combined with the end-game science-fiction Stardust minion weapons, it can be unstoppable.
But, the whip is a 25% drop from the Empress of Light boss, which is one of the hardest bosses. So, players will have to struggle a lot to get this. Kaleidoscope also has a weak knockback, so it may not work as well with swarms of mobs.
Firecracker
After defeating the Wall of Flesh, one of the possible drops is the Firecracker whip. When this whip targets an enemy, a minion hitting it will cause an explosion. This explosion always causes about 2.75 times the damage the minion did to the enemy.
Although this whip has a much lower base damage compared to later hardmode whips, the explosion ability makes it possibly more powerful as long as the player has strong minions. Combined with the "On Fire!" debuff this inflicts, the Firecracker is an unexpectedly useful end-game weapon.
Durendal
Using 12 Hallowed Bars at either a Mythril or Orichalcum Anvil, the player can possibly make a Durendal whip. If an enemy is hit by this whip, the player will get the "Durendal's Blessing," which increases attack speed. This whip also has a relatively high base damage and summon tag damage.
While this whip is not as powerful on its own as other hardmode whips and it also does not have as much range, it becomes incredibly powerful when used with other hardmode whips because of the speed buff. Also, it is much easier to obtain compared to other whips.